标签: ecmascript-harmony

考虑这段代码：

function foo(a) {
  console.log("Mul =", a);
  return a * 2;
};

function * process(start) {
  // next() #1
  var result = start;

  console.log("Pre-processing =", result);
  result = yield foo(result);
  // next() #2
  console.log("Process result 1 =", result);
  result = yield foo(result);
  // next() #3
  console.log("Process result 2 =", result);
  result = yield foo(result);
  // next() #4
  console.log("Process result 3 =", result);

  return foo(result);
}

var it = process(1);
console.log("#1");
console.log("Next 1 =", /*#1*/it.next("bar"));
console.log("#2");
console.log("Next 2 =", /*#2*/it.next(3));
console.log("#3"); …

我正在写生成器的简单函数

function simpleGenerator(){
  yield "first";
  yield "second";
  yield "third";
};
var g = simpleGenerator();
console.log(g.next());

它是为了屈服线——

SyntaxError: missing ; before statement

我无法得到显示错误的原因...如果我使用 return like

function simpleGenerator(x){
 while(true){
  var a=x*2;
  return a;
 }
}
var g = simpleGenerator(2);
console.log(g);

它工作正常，

问题是:

longhao33@hePC:~$ node --harmony test.js 
/home/longhao33/test.js:1
(function (exports, require, module, __filename, __dirname) { let str = 'es666666666666';
                                                              ^^^

SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:413:25)
    at Object.Module._extensions..js (module.js:452:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Function.Module.runMain (module.js:475:10)
    at startup (node.js:117:18)
    at node.js:951:3

但是:"让"在以下情况下得到支持:(太奇怪了!)

longhao33@hePC:~$ node --harmony
> let str = 'es66666666666'
undefined
> str
'es66666666666'

1. 系统:ubuntu 14.04LTS 64bit
2. node:V4.1.1(由nvm安装,安装在$ HOME)

3. test.js的内容:

   让str ='es666666666666'; 的console.log(STR);

提前谢谢.

ES5和ES6之间的行为差​​异要小得多.这些差异可能会导致在使用现代浏览器(支持ES6)进行解释时在ES5中编写的脚本出错.这个问题如何解决？