PHP 中 var_dump 或 print_r 在 JavaScript 中的等价物是什么？

Question

我想查看 JavaScript 中对象的结构（用于调试）。 PHP中有类似var_dump的东西吗？

Answer 1

大多数现代浏览器的开发工具中都有一个控制台，对于此类调试很有用。

console.log(myvar);

然后，您将在控制台中获得一个精心映射的对象/任何内容的界面。

查看控制台文档更多细节。

Answer 2

最常见的方法：

console.log(object);

但是我必须提到 JSON.stringify 这对于转储非浏览器脚本中的变量很有用：

console.log( JSON.stringify(object) );

JSON.stringify 函数还支持内置的美化功能作者：Simon Zyx。

示例：

var obj = {x: 1, y: 2, z: 3};

console.log( JSON.stringify(obj, null, 2) ); // spacing level = 2

上面的代码片段将打印：

{
  "x": 1,
  "y": 2,
  "z": 3
}

在 caniuse.com 上，您可以查看原生支持 JSON.stringify 函数的浏览器：http://caniuse.com/json

您还可以使用 Douglas Crockford 库在旧浏览器上添加 JSON.stringify 支持：< a href="https://github.com/douglascrockford/JSON-js" rel="noreferrer">https://github.com/douglascrockford/JSON-js

JSON.stringify< 的文档/code>: https://developer.mozilla .org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify

我希望这有帮助:-)

Answer 3

我编写了这个 JS 函数 dump()，使其像 PHP 的 var_dump() 一样工作。
要在警报窗口中显示变量的内容：dump(variable)
在网页中显示变量的内容：dump(variable, 'body')
仅获取变量的字符串：dump(variable, 'none')

/* repeatString() returns a string which has been repeated a set number of times */
function repeatString(str, num) {
    out = '';
    for (var i = 0; i < num; i++) {
        out += str;
    }
    return out;
}

/*
dump() displays the contents of a variable like var_dump() does in PHP. dump() is
better than typeof, because it can distinguish between array, null and object.
Parameters:
    v:              The variable
    howDisplay:     "none", "body", "alert" (default)
    recursionLevel: Number of times the function has recursed when entering nested
                    objects or arrays. Each level of recursion adds extra space to the
                    output to indicate level. Set to 0 by default.
Return Value:
    A string of the variable's contents
Limitations:
    Can't pass an undefined variable to dump(). 
    dump() can't distinguish between int and float.
    dump() can't tell the original variable type of a member variable of an object.
    These limitations can't be fixed because these are *features* of JS. However, dump()
*/
function dump(v, howDisplay, recursionLevel) {
    howDisplay = (typeof howDisplay === 'undefined') ? "alert" : howDisplay;
    recursionLevel = (typeof recursionLevel !== 'number') ? 0 : recursionLevel;

    var vType = typeof v;
    var out = vType;

    switch (vType) {
        case "number":
        /* there is absolutely no way in JS to distinguish 2 from 2.0
           so 'number' is the best that you can do. The following doesn't work:
           var er = /^[0-9]+$/;
           if (!isNaN(v) && v % 1 === 0 && er.test(3.0)) {
               out = 'int';
           }
        */
        break;
    case "boolean":
        out += ": " + v;
        break;
    case "string":
        out += "(" + v.length + '): "' + v + '"';
        break;
    case "object":
        //check if null
        if (v === null) {
            out = "null";
        }
        //If using jQuery: if ($.isArray(v))
        //If using IE: if (isArray(v))
        //this should work for all browsers according to the ECMAScript standard:
        else if (Object.prototype.toString.call(v) === '[object Array]') {
            out = 'array(' + v.length + '): {\n';
            for (var i = 0; i < v.length; i++) {
                out += repeatString('   ', recursionLevel) + "   [" + i + "]:  " +
                    dump(v[i], "none", recursionLevel + 1) + "\n";
            }
            out += repeatString('   ', recursionLevel) + "}";
        }
        else {
            //if object
            let sContents = "{\n";
            let cnt = 0;
            for (var member in v) {
                //No way to know the original data type of member, since JS
                //always converts it to a string and no other way to parse objects.
                sContents += repeatString('   ', recursionLevel) + "   " + member +
                    ":  " + dump(v[member], "none", recursionLevel + 1) + "\n";
                cnt++;
            }
            sContents += repeatString('   ', recursionLevel) + "}";
            out += "(" + cnt + "): " + sContents;
        }
        break;
    default:
        out = v;
        break;
    }

    if (howDisplay == 'body') {
        var pre = document.createElement('pre');
        pre.innerHTML = out;
        document.body.appendChild(pre);
    }
    else if (howDisplay == 'alert') {
        alert(out);
    }

    return out;
}

Answer 4

JavaScript 中的 var_dump 等效项？ 很简单，没有一个。

但是，这并不意味着您无助。 就像一些人建议的那样，使用 Firebug （或其他浏览器中的等效项），但与其他人建议的不同，不要使用控制台.log 当你有一个（稍微）更好的工具 console.dir< /a>：

console.dir(object)

打印对象所有属性的交互式列表。 这
看起来与您在 DOM 选项卡中看到的视图相同。

Answer 5

正如其他人已经提到的，调试变量的最佳方法是使用现代浏览器的开发人员控制台（例如 Chrome 开发人员工具< /a>、Firefox+Firebug、Opera Dragonfly > _{（现在在新的基于 Chromium 的 (Blink) Opera 中消失了，但作为开发人员 说，“尽管我们还无法向您提供更多信息，但 Dragonfly 并未消亡”）}。

但是，如果您需要其他方法，有一个非常有用的网站，名为
php.js：

http://phpjs.org/

提供 “PHP 函数的 JavaScript 替代品” - 因此您可以像在 PHP 中一样使用它们。 我将在此处将适当的函数复制粘贴给您，但是请注意，如果检测到某些错误，这些代码可以在原始站点上更新，因此我建议您访问 phpjs.org 网站！ （顺便说一句。我不隶属于该网站，但我发现它非常有用。）

JavaScript 中的 var_dump()

下面是 var_dump() 的 JS 替代代码代码>:
http://phpjs.org/functions/var_dump/
它取决于 echo() 函数：http://phpjs.org/functions/echo/

function var_dump() {
  //  discuss at: http://phpjs.org/functions/var_dump/
  // original by: Brett Zamir (http://brett-zamir.me)
  // improved by: Zahlii
  // improved by: Brett Zamir (http://brett-zamir.me)
  //  depends on: echo
  //        note: For returning a string, use var_export() with the second argument set to true
  //        test: skip
  //   example 1: var_dump(1);
  //   returns 1: 'int(1)'

  var output = '',
    pad_char = ' ',
    pad_val = 4,
    lgth = 0,
    i = 0;

  var _getFuncName = function(fn) {
    var name = (/\W*function\s+([\w\$]+)\s*\(/)
      .exec(fn);
    if (!name) {
      return '(Anonymous)';
    }
    return name[1];
  };

  var _repeat_char = function(len, pad_char) {
    var str = '';
    for (var i = 0; i < len; i++) {
      str += pad_char;
    }
    return str;
  };
  var _getInnerVal = function(val, thick_pad) {
    var ret = '';
    if (val === null) {
      ret = 'NULL';
    } else if (typeof val === 'boolean') {
      ret = 'bool(' + val + ')';
    } else if (typeof val === 'string') {
      ret = 'string(' + val.length + ') "' + val + '"';
    } else if (typeof val === 'number') {
      if (parseFloat(val) == parseInt(val, 10)) {
        ret = 'int(' + val + ')';
      } else {
        ret = 'float(' + val + ')';
      }
    }
    // The remaining are not PHP behavior because these values only exist in this exact form in JavaScript
    else if (typeof val === 'undefined') {
      ret = 'undefined';
    } else if (typeof val === 'function') {
      var funcLines = val.toString()
        .split('\n');
      ret = '';
      for (var i = 0, fll = funcLines.length; i < fll; i++) {
        ret += (i !== 0 ? '\n' + thick_pad : '') + funcLines[i];
      }
    } else if (val instanceof Date) {
      ret = 'Date(' + val + ')';
    } else if (val instanceof RegExp) {
      ret = 'RegExp(' + val + ')';
    } else if (val.nodeName) {
      // Different than PHP's DOMElement
      switch (val.nodeType) {
      case 1:
        if (typeof val.namespaceURI === 'undefined' || val.namespaceURI === 'http://www.w3.org/1999/xhtml') {
          // Undefined namespace could be plain XML, but namespaceURI not widely supported
          ret = 'HTMLElement("' + val.nodeName + '")';
        } else {
          ret = 'XML Element("' + val.nodeName + '")';
        }
        break;
      case 2:
        ret = 'ATTRIBUTE_NODE(' + val.nodeName + ')';
        break;
      case 3:
        ret = 'TEXT_NODE(' + val.nodeValue + ')';
        break;
      case 4:
        ret = 'CDATA_SECTION_NODE(' + val.nodeValue + ')';
        break;
      case 5:
        ret = 'ENTITY_REFERENCE_NODE';
        break;
      case 6:
        ret = 'ENTITY_NODE';
        break;
      case 7:
        ret = 'PROCESSING_INSTRUCTION_NODE(' + val.nodeName + ':' + val.nodeValue + ')';
        break;
      case 8:
        ret = 'COMMENT_NODE(' + val.nodeValue + ')';
        break;
      case 9:
        ret = 'DOCUMENT_NODE';
        break;
      case 10:
        ret = 'DOCUMENT_TYPE_NODE';
        break;
      case 11:
        ret = 'DOCUMENT_FRAGMENT_NODE';
        break;
      case 12:
        ret = 'NOTATION_NODE';
        break;
      }
    }
    return ret;
  };

  var _formatArray = function(obj, cur_depth, pad_val, pad_char) {
    var someProp = '';
    if (cur_depth > 0) {
      cur_depth++;
    }

    var base_pad = _repeat_char(pad_val * (cur_depth - 1), pad_char);
    var thick_pad = _repeat_char(pad_val * (cur_depth + 1), pad_char);
    var str = '';
    var val = '';

    if (typeof obj === 'object' && obj !== null) {
      if (obj.constructor && _getFuncName(obj.constructor) === 'PHPJS_Resource') {
        return obj.var_dump();
      }
      lgth = 0;
      for (someProp in obj) {
        lgth++;
      }
      str += 'array(' + lgth + ') {\n';
      for (var key in obj) {
        var objVal = obj[key];
        if (typeof objVal === 'object' && objVal !== null && !(objVal instanceof Date) && !(objVal instanceof RegExp) &&
          !
          objVal.nodeName) {
          str += thick_pad + '[' + key + '] =>\n' + thick_pad + _formatArray(objVal, cur_depth + 1, pad_val,
            pad_char);
        } else {
          val = _getInnerVal(objVal, thick_pad);
          str += thick_pad + '[' + key + '] =>\n' + thick_pad + val + '\n';
        }
      }
      str += base_pad + '}\n';
    } else {
      str = _getInnerVal(obj, thick_pad);
    }
    return str;
  };

  output = _formatArray(arguments[0], 0, pad_val, pad_char);
  for (i = 1; i < arguments.length; i++) {
    output += '\n' + _formatArray(arguments[i], 0, pad_val, pad_char);
  }

  this.echo(output);
}

JavaScript 中的 print_r()

下面是 print_r() 函数：
http://phpjs.org/functions/print_r/
它也取决于 echo()。

function print_r(array, return_val) {
  //  discuss at: http://phpjs.org/functions/print_r/
  // original by: Michael White (http://getsprink.com)
  // improved by: Ben Bryan
  // improved by: Brett Zamir (http://brett-zamir.me)
  // improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  //    input by: Brett Zamir (http://brett-zamir.me)
  //  depends on: echo
  //   example 1: print_r(1, true);
  //   returns 1: 1

  var output = '',
    pad_char = ' ',
    pad_val = 4,
    d = this.window.document,
    getFuncName = function(fn) {
      var name = (/\W*function\s+([\w\$]+)\s*\(/)
        .exec(fn);
      if (!name) {
        return '(Anonymous)';
      }
      return name[1];
    };
  repeat_char = function(len, pad_char) {
    var str = '';
    for (var i = 0; i < len; i++) {
      str += pad_char;
    }
    return str;
  };
  formatArray = function(obj, cur_depth, pad_val, pad_char) {
    if (cur_depth > 0) {
      cur_depth++;
    }

    var base_pad = repeat_char(pad_val * cur_depth, pad_char);
    var thick_pad = repeat_char(pad_val * (cur_depth + 1), pad_char);
    var str = '';

    if (typeof obj === 'object' && obj !== null && obj.constructor && getFuncName(obj.constructor) !==
      'PHPJS_Resource') {
      str += 'Array\n' + base_pad + '(\n';
      for (var key in obj) {
        if (Object.prototype.toString.call(obj[key]) === '[object Array]') {
          str += thick_pad + '[' + key + '] => ' + formatArray(obj[key], cur_depth + 1, pad_val, pad_char);
        } else {
          str += thick_pad + '[' + key + '] => ' + obj[key] + '\n';
        }
      }
      str += base_pad + ')\n';
    } else if (obj === null || obj === undefined) {
      str = '';
    } else {
      // for our "resource" class
      str = obj.toString();
    }

    return str;
  };

  output = formatArray(array, 0, pad_val, pad_char);

  if (return_val !== true) {
    if (d.body) {
      this.echo(output);
    } else {
      try {
        // We're in XUL, so appending as plain text won't work; trigger an error out of XUL
        d = XULDocument;
        this.echo('<pre xmlns="http://www.w3.org/1999/xhtml" style="white-space:pre;">' + output + '</pre>');
      } catch (e) {
        // Outputting as plain text may work in some plain XML
        this.echo(output);
      }
    }
    return true;
  }
  return output;
}

JavaScript 中的 var_export()

您可能还会发现 var_export() 替代方案很有用，它也依赖于 echo()：
JavaScript 中的http://phpjs.org/functions/var_export/

function var_export(mixed_expression, bool_return) {
  //  discuss at: http://phpjs.org/functions/var_export/
  // original by: Philip Peterson
  // improved by: johnrembo
  // improved by: Brett Zamir (http://brett-zamir.me)
  //    input by: Brian Tafoya (http://www.premasolutions.com/)
  //    input by: Hans Henrik (http://hanshenrik.tk/)
  // bugfixed by: Brett Zamir (http://brett-zamir.me)
  // bugfixed by: Brett Zamir (http://brett-zamir.me)
  //  depends on: echo
  //   example 1: var_export(null);
  //   returns 1: null
  //   example 2: var_export({0: 'Kevin', 1: 'van', 2: 'Zonneveld'}, true);
  //   returns 2: "array (\n  0 => 'Kevin',\n  1 => 'van',\n  2 => 'Zonneveld'\n)"
  //   example 3: data = 'Kevin';
  //   example 3: var_export(data, true);
  //   returns 3: "'Kevin'"

  var retstr = '',
    iret = '',
    value,
    cnt = 0,
    x = [],
    i = 0,
    funcParts = [],
    // We use the last argument (not part of PHP) to pass in
    // our indentation level
    idtLevel = arguments[2] || 2,
    innerIndent = '',
    outerIndent = '',
    getFuncName = function(fn) {
      var name = (/\W*function\s+([\w\$]+)\s*\(/)
        .exec(fn);
      if (!name) {
        return '(Anonymous)';
      }
      return name[1];
    };
  _makeIndent = function(idtLevel) {
    return (new Array(idtLevel + 1))
      .join(' ');
  };
  __getType = function(inp) {
    var i = 0,
      match, types, cons, type = typeof inp;
    if (type === 'object' && (inp && inp.constructor) &&
      getFuncName(inp.constructor) === 'PHPJS_Resource') {
      return 'resource';
    }
    if (type === 'function') {
      return 'function';
    }
    if (type === 'object' && !inp) {
      // Should this be just null?
      return 'null';
    }
    if (type === 'object') {
      if (!inp.constructor) {
        return 'object';
      }
      cons = inp.constructor.toString();
      match = cons.match(/(\w+)\(/);
      if (match) {
        cons = match[1].toLowerCase();
      }
      types = ['boolean', 'number', 'string', 'array'];
      for (i = 0; i < types.length; i++) {
        if (cons === types[i]) {
          type = types[i];
          break;
        }
      }
    }
    return type;
  };
  type = __getType(mixed_expression);

  if (type === null) {
    retstr = 'NULL';
  } else if (type === 'array' || type === 'object') {
    outerIndent = _makeIndent(idtLevel - 2);
    innerIndent = _makeIndent(idtLevel);
    for (i in mixed_expression) {
      value = this.var_export(mixed_expression[i], 1, idtLevel + 2);
      value = typeof value === 'string' ? value.replace(/</g, '<')
        .
      replace(/>/g, '>'): value;
      x[cnt++] = innerIndent + i + ' => ' +
        (__getType(mixed_expression[i]) === 'array' ?
          '\n' : '') + value;
    }
    iret = x.join(',\n');
    retstr = outerIndent + 'array (\n' + iret + '\n' + outerIndent + ')';
  } else if (type === 'function') {
    funcParts = mixed_expression.toString()
      .
    match(/function .*?\((.*?)\) \{([\s\S]*)\}/);

    // For lambda functions, var_export() outputs such as the following:
    // '\000lambda_1'. Since it will probably not be a common use to
    // expect this (unhelpful) form, we'll use another PHP-exportable
    // construct, create_function() (though dollar signs must be on the
    // variables in JavaScript); if using instead in JavaScript and you
    // are using the namespaced version, note that create_function() will
    // not be available as a global
    retstr = "create_function ('" + funcParts[1] + "', '" +
      funcParts[2].replace(new RegExp("'", 'g'), "\\'") + "')";
  } else if (type === 'resource') {
    // Resources treated as null for var_export
    retstr = 'NULL';
  } else {
    retstr = typeof mixed_expression !== 'string' ? mixed_expression :
      "'" + mixed_expression.replace(/(["'])/g, '\\$1')
      .
    replace(/\0/g, '\\0') + "'";
  }

  if (!bool_return) {
    this.echo(retstr);
    return null;
  }

  return retstr;
}

echo()

http://phpjs.org/functions/echo/

function echo() {
  //  discuss at: http://phpjs.org/functions/echo/
  // original by: Philip Peterson
  // improved by: echo is bad
  // improved by: Nate
  // improved by: Brett Zamir (http://brett-zamir.me)
  // improved by: Brett Zamir (http://brett-zamir.me)
  // improved by: Brett Zamir (http://brett-zamir.me)
  //  revised by: Der Simon (http://innerdom.sourceforge.net/)
  // bugfixed by: Eugene Bulkin (http://doubleaw.com/)
  // bugfixed by: Brett Zamir (http://brett-zamir.me)
  // bugfixed by: Brett Zamir (http://brett-zamir.me)
  // bugfixed by: EdorFaus
  //    input by: JB
  //        note: If browsers start to support DOM Level 3 Load and Save (parsing/serializing),
  //        note: we wouldn't need any such long code (even most of the code below). See
  //        note: link below for a cross-browser implementation in JavaScript. HTML5 might
  //        note: possibly support DOMParser, but that is not presently a standard.
  //        note: Although innerHTML is widely used and may become standard as of HTML5, it is also not ideal for
  //        note: use with a temporary holder before appending to the DOM (as is our last resort below),
  //        note: since it may not work in an XML context
  //        note: Using innerHTML to directly add to the BODY is very dangerous because it will
  //        note: break all pre-existing references to HTMLElements.
  //   example 1: echo('<div><p>abc</p><p>abc</p></div>');
  //   returns 1: undefined

  var isNode = typeof module !== 'undefined' && module.exports && typeof global !== "undefined" && {}.toString.call(
    global) == '[object global]';
  if (isNode) {
    var args = Array.prototype.slice.call(arguments);
    return console.log(args.join(' '));
  }

  var arg = '';
  var argc = arguments.length;
  var argv = arguments;
  var i = 0;
  var holder, win = this.window;
  var d = win.document;
  var ns_xhtml = 'http://www.w3.org/1999/xhtml';
  // If we're in a XUL context
  var ns_xul = 'http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul';

  var stringToDOM = function(str, parent, ns, container) {
    var extraNSs = '';
    if (ns === ns_xul) {
      extraNSs = ' xmlns:html="' + ns_xhtml + '"';
    }
    var stringContainer = '<' + container + ' xmlns="' + ns + '"' + extraNSs + '>' + str + '</' + container + '>';
    var dils = win.DOMImplementationLS;
    var dp = win.DOMParser;
    var ax = win.ActiveXObject;
    if (dils && dils.createLSInput && dils.createLSParser) {
      // Follows the DOM 3 Load and Save standard, but not
      // implemented in browsers at present; HTML5 is to standardize on innerHTML, but not for XML (though
      // possibly will also standardize with DOMParser); in the meantime, to ensure fullest browser support, could
      // attach http://svn2.assembla.com/svn/brettz9/DOMToString/DOM3.js (see http://svn2.assembla.com/svn/brettz9/DOMToString/DOM3.xhtml for a simple test file)
      var lsInput = dils.createLSInput();
      // If we're in XHTML, we'll try to allow the XHTML namespace to be available by default
      lsInput.stringData = stringContainer;
      // synchronous, no schema type
      var lsParser = dils.createLSParser(1, null);
      return lsParser.parse(lsInput)
        .firstChild;
    } else if (dp) {
      // If we're in XHTML, we'll try to allow the XHTML namespace to be available by default
      try {
        var fc = new dp()
          .parseFromString(stringContainer, 'text/xml');
        if (fc && fc.documentElement && fc.documentElement.localName !== 'parsererror' && fc.documentElement.namespaceURI !==
          'http://www.mozilla.org/newlayout/xml/parsererror.xml') {
          return fc.documentElement.firstChild;
        }
        // If there's a parsing error, we just continue on
      } catch (e) {
        // If there's a parsing error, we just continue on
      }
    } else if (ax) {
      // We don't bother with a holder in Explorer as it doesn't support namespaces
      var axo = new ax('MSXML2.DOMDocument');
      axo.loadXML(str);
      return axo.documentElement;
    }
    /*else if (win.XMLHttpRequest) {
     // Supposed to work in older Safari
      var req = new win.XMLHttpRequest;
      req.open('GET', 'data:application/xml;charset=utf-8,'+encodeURIComponent(str), false);
      if (req.overrideMimeType) {
        req.overrideMimeType('application/xml');
      }
      req.send(null);
      return req.responseXML;
    }*/
    // Document fragment did not work with innerHTML, so we create a temporary element holder
    // If we're in XHTML, we'll try to allow the XHTML namespace to be available by default
    //if (d.createElementNS && (d.contentType && d.contentType !== 'text/html')) {
    // Don't create namespaced elements if we're being served as HTML (currently only Mozilla supports this detection in true XHTML-supporting browsers, but Safari and Opera should work with the above DOMParser anyways, and IE doesn't support createElementNS anyways)
    if (d.createElementNS && // Browser supports the method
      (d.documentElement.namespaceURI || // We can use if the document is using a namespace
        d.documentElement.nodeName.toLowerCase() !== 'html' || // We know it's not HTML4 or less, if the tag is not HTML (even if the root namespace is null)
        (d.contentType && d.contentType !== 'text/html') // We know it's not regular HTML4 or less if this is Mozilla (only browser supporting the attribute) and the content type is something other than text/html; other HTML5 roots (like svg) still have a namespace
      )) {
      // Don't create namespaced elements if we're being served as HTML (currently only Mozilla supports this detection in true XHTML-supporting browsers, but Safari and Opera should work with the above DOMParser anyways, and IE doesn't support createElementNS anyways); last test is for the sake of being in a pure XML document
      holder = d.createElementNS(ns, container);
    } else {
      // Document fragment did not work with innerHTML
      holder = d.createElement(container);
    }
    holder.innerHTML = str;
    while (holder.firstChild) {
      parent.appendChild(holder.firstChild);
    }
    return false;
    // throw 'Your browser does not support DOM parsing as required by echo()';
  };

  var ieFix = function(node) {
    if (node.nodeType === 1) {
      var newNode = d.createElement(node.nodeName);
      var i, len;
      if (node.attributes && node.attributes.length > 0) {
        for (i = 0, len = node.attributes.length; i < len; i++) {
          newNode.setAttribute(node.attributes[i].nodeName, node.getAttribute(node.attributes[i].nodeName));
        }
      }
      if (node.childNodes && node.childNodes.length > 0) {
        for (i = 0, len = node.childNodes.length; i < len; i++) {
          newNode.appendChild(ieFix(node.childNodes[i]));
        }
      }
      return newNode;
    } else {
      return d.createTextNode(node.nodeValue);
    }
  };

  var replacer = function(s, m1, m2) {
    // We assume for now that embedded variables do not have dollar sign; to add a dollar sign, you currently must use {$var} (We might change this, however.)
    // Doesn't cover all cases yet: see http://php.net/manual/en/language.types.string.php#language.types.string.syntax.double
    if (m1 !== '\\') {
      return m1 + eval(m2);
    } else {
      return s;
    }
  };

  this.php_js = this.php_js || {};
  var phpjs = this.php_js;
  var ini = phpjs.ini;
  var obs = phpjs.obs;
  for (i = 0; i < argc; i++) {
    arg = argv[i];
    if (ini && ini['phpjs.echo_embedded_vars']) {
      arg = arg.replace(/(.?)\{?\$(\w*?\}|\w*)/g, replacer);
    }

    if (!phpjs.flushing && obs && obs.length) {
      // If flushing we output, but otherwise presence of a buffer means caching output
      obs[obs.length - 1].buffer += arg;
      continue;
    }

    if (d.appendChild) {
      if (d.body) {
        if (win.navigator.appName === 'Microsoft Internet Explorer') {
          // We unfortunately cannot use feature detection, since this is an IE bug with cloneNode nodes being appended
          d.body.appendChild(stringToDOM(ieFix(arg)));
        } else {
          var unappendedLeft = stringToDOM(arg, d.body, ns_xhtml, 'div')
            .cloneNode(true); // We will not actually append the div tag (just using for providing XHTML namespace by default)
          if (unappendedLeft) {
            d.body.appendChild(unappendedLeft);
          }
        }
      } else {
        // We will not actually append the description tag (just using for providing XUL namespace by default)
        d.documentElement.appendChild(stringToDOM(arg, d.documentElement, ns_xul, 'description'));
      }
    } else if (d.write) {
      d.write(arg);
    } else {
      console.log(arg);
    }
  }
}

Answer 6

Firebug。

然后，在您的 javascript 中：

var blah = {something: 'hi', another: 'noway'};
console.debug("Here is blah: %o", blah);

现在您可以查看控制台，单击该语句并查看里面的内容 blah

Answer 7

一个很好的简单解决方案，用于解析 HTML 的 JSON 响应。

var json_response = jQuery.parseJSON(data);
html_response += 'JSON Response:<br />';

jQuery.each(json_response, function(k, v) {
    html_response += outputJSONReponse(k, v);
});

function outputJSONReponse(k, v) {
    var html_response = k + ': ';

    if(jQuery.isArray(v) || jQuery.isPlainObject(v)) {
        jQuery.each(v, function(j, w) {
            html_response += outputJSONReponse(j, w);
        });
    } else {
        html_response += v + '<br />';
    }

    return html_response;
}

Answer 8

你也可以试试这个功能。 我不记得原作者了，但所有的功劳都归他们所有。

工作起来就像一个魅力 - 与 PHP 中的 var_dump 100% 相同。

一探究竟。

function dump(arr,level) {
    var dumped_text = "";
    if(!level) level = 0;

    //The padding given at the beginning of the line.
    var level_padding = "";
    for(var j=0;j<level+1;j++) level_padding += "    ";

    if(typeof(arr) == 'object') { //Array/Hashes/Objects
        for(var item in arr) {
            var value = arr[item];

            if(typeof(value) == 'object') { //If it is an array,
                dumped_text += level_padding + "'" + item + "' ...\n";
                dumped_text += dump(value,level+1);
            } else {
                dumped_text += level_padding + "'" + item + "' => \"" + value + "\"\n";
            }
        }
    } else { //Stings/Chars/Numbers etc.
        dumped_text = "===>"+arr+"<===("+typeof(arr)+")";
    }
    return dumped_text;
}


// Example:

var employees = [
    { id: '1', sex: 'm', city: 'Paris' }, 
    { id: '2', sex: 'f', city: 'London' },
    { id: '3', sex: 'f', city: 'New York' },
    { id: '4', sex: 'm', city: 'Moscow' },
    { id: '5', sex: 'm', city: 'Berlin' }
]


// Open dev console (F12) to see results:

console.log(dump(employees));

Answer 9

我提出这个是为了帮助任何需要一些实用的东西的人，为您提供一个漂亮的、美化的（缩进的）JS Node 图片。 对于节点（“循环错误”或其他什么......），其他解决方案都不适合我。 这将引导您浏览 DOM Node 下的树（不使用递归），并为您提供深度、tagName（如果适用）和 textContent （如果适用）。

您在头节点下行走树时遇到的节点的任何其他详细信息都可以根据您的兴趣添加...

function printRNode( node ){
    // make sort of human-readable picture of the node... a bit like PHP print_r

    if( node === undefined || node === null ){
        throwError( 'node was ' + typeof node );
    }
    let s = '';

    // NB walkDOM could be made into a utility function which you could 
    // call with one or more callback functions as parameters...

    function walkDOM( headNode ){
      const stack = [ headNode ];
      const depthCountDowns = [ 1 ];
      while (stack.length > 0) {
        const node = stack.pop();
        const depth = depthCountDowns.length - 1;
        // TODO non-text, non-BR nodes could show more details (attributes, properties, etc.)
        const stringRep = node.nodeType === 3? 'TEXT: |' + node.nodeValue + '|' : 'tag: ' + node.tagName;
        s += '  '.repeat( depth ) + stringRep + '\n';
        const lastIndex = depthCountDowns.length - 1;
        depthCountDowns[ lastIndex ] = depthCountDowns[ lastIndex ] - 1;
        if( node.childNodes.length ){
            depthCountDowns.push( node.childNodes.length );
            stack.push( ... Array.from( node.childNodes ).reverse() );
        }
        while( depthCountDowns[ depthCountDowns.length - 1 ] === 0 ){
            depthCountDowns.splice( -1 );
        }
      }
    } 
    walkDOM( node );
    return s;
}