功能和功能有什么区别*

Question

使用function和function*

创建的生成器函数之间有什么区别

function a(i){
    for(;i>0;i--){
        yield i*i;
    }
}
function *b(i){
    for(;i>0;i--){
        yield i*i*i;
    }
}

Answer 1

使用function创建的生成器是早期ES6草案的一部分。

//They have differrent prototypes
console.log(a.prototype.constructor.constructor,b.prototype.constructor.constructor);//function Function() function GeneratorFunction()
let a1=a(10);
let b1=b(10);
//both create generators...
console.log(a1,b1);//Generator {  } Generator {  }
//but different generators: one returns value, another returns an object of special format
console.log(a1.next(),b1.next());//100 Object { value: 1000, done: false }
for(let a2 of a1)console.log(a2);
for(let b2 of b1)console.log(b2);
//They are equal when used in for ... of.