catch 语句可以捕获 JavaScript 中的语法错误吗？
Kangax 博客有一个代码示例：§
try {
(var x = 5); // grouping operator can only contain expression, not a statement (which `var` is)
} catch(err) {
// SyntaxError
}
第2行的语法错误会影响“整个代码的语法”，这里的catch语句有什么意义？
catch 能够捕获 JavaScript 中的语法错误吗？
Kangax blog has a code example: §
try {
(var x = 5); // grouping operator can only contain expression, not a statement (which `var` is)
} catch(err) {
// SyntaxError
}
Since the syntax error at line 2 would affect the "syntax of the entire code", what's the point of the catch statement here?
Is catch able to catch syntax errors in JavaScript?
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评论（3）
你是对的，javascript 解析器会生成一个错误，所以它永远不会捕获它。
http://jsbin.com/oluje5/edit
也许他的意图是指出错误的语法（分组运算符只能包含表达式，不能包含语句），但try/catch语句没有用。
此外，catch 中的注释
//syntaxError让我们假设 catch 会执行某些操作。You are right, javascript parser will generate an error, so it will never catch it.
http://jsbin.com/oluje5/edit
Maybe his intention was to point out the wrong syntax (grouping operator can only contain expression, not a statement), but the try / catch statement is useless.
Moreover, the comment
//syntaxErrorinside catch let suppose that the catch will do something.不，这是正确的。使用
try...catch无助于解决语法错误。如果存在语法错误导致脚本块无法被解析，则脚本块根本不会运行。
No, that is correct. Using a
try...catchdoesn't help against syntax errors.The script block won't run at all if there is a syntax error keeping it from being parsed.
try/catch 不会捕获语法错误，因为您不能像这样将变量赋值包含在括号中。
Syntax errors wont be caught by try/catch, as you can't wrap variable assignments in brackets like that.