Function.displayName - JavaScript 编辑

Non-standard

This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

The function.displayName property returns the display name of the function.

Examples

Setting a displayName

It is usually preferred by consoles and profilers over func.name to display the name of a function.

By entering the following in a console, it should display as something like "function My Function()":

var a = function() {};
a.displayName = 'My Function';

a; // "function My Function()"

When defined, the displayName property returns the display name of a function:

function doSomething() {}

console.log(doSomething.displayName); // "undefined"

var popup = function(content) { console.log(content); };

popup.displayName = 'Show Popup';

console.log(popup.displayName); // "Show Popup"

Defining a displayName in function expressions

You can define a function with a display name in a function expression:

var object = {
  someMethod: function() {}
};

object.someMethod.displayName = 'someMethod';

console.log(object.someMethod.displayName); // logs "someMethod"

try { someMethod } catch(e) { console.log(e); }
// ReferenceError: someMethod is not defined

Changing displayName dynamically

You can dynamically change the displayName of a function:

var object = {
  // anonymous
  someMethod: function(value) {
    arguments.callee.displayName = 'someMethod (' + value + ')';
  }
};

console.log(object.someMethod.displayName); // "undefined"

object.someMethod('123')
console.log(object.someMethod.displayName); // "someMethod (123)"

Specifications

Not part of any standard.

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• Function.name