JavaScript:可以使用单引号 5's Strict Mode (") 启用 ECMAScript ('use strict' use strict") 吗？

Question

JavaScript 不关心字符串是双引号 "double" 还是单引号 'single'。

ECMAScript 5 严格模式的每个示例都通过双引号中的 "use strict" 启用。我可以执行以下操作吗(单引号):

alert(function(){
  'use strict';
  return !this;
}());

如果启用严格模式，这将返回 true，否则返回 false。

Answer 1

For you, without using a browser that supports strict mode :

A Use Strict Directive is an ExpressionStatement in a Directive Prologue whose StringLiteral is either the exact character sequences "use strict" or 'use strict'. A Use Strict Directive may not contain an EscapeSequence or LineContinuation.