'use strict';
function next_id(){
var id = 1;
while(id<100){
yield id;
id++;
}
return id;
}
// 測試:
var
x,
pass = true,
g = next_id();
for (x = 1; x < 100; x ++) {
if (g.next().value !== x) {
pass = false;
alert('測試失敗!');
break;
}
}
if (pass) {
alert('測試通過!');
}

2.2 一個(gè)無限循環(huán)的迭代器

function* idMaker(){
var index = 0;
while(true)
yield index++;
}
var gen = idMaker(); // "Generator { }"
console.log(gen.next().value); // 0
console.log(gen.next().value); // 1
console.log(gen.next().value); // 2

2.3Generator.prototype.next()

當(dāng)?shù)Y(jié)束時(shí)， Generator.next().done ===true, 結(jié)束之前 ===false

function* gen() { 
yield 1;
yield 2;
yield 3;
}
var g = gen(); // "Generator { }"
g.next(); // "Object { value: 1, done: false }"
g.next(); // "Object { value: 2, done: false }"
g.next(); // "Object { value: 3, done: false }"
g.next(); // "Object { value: undefined, done: true }"

2.4 Generator.prototype.return();

return方法返回給定的參數(shù)值，并結(jié)束迭代器

example

function* gen() { 
yield 1;
yield 2;
yield 3;
}
var g = gen();
g.next(); // { value: 1, done: false }
g.return("foo"); // { value: "foo", done: true }
g.next(); // { value: undefined, done: true }

注意如果 done的值是true了，再調(diào)用return，返回的值也是undefined

function* gen() {yield 1;}
var g = gen();
console.log(g.next());//{ value: 1, done: false }
console.log(g.next());//{ value: undefined, done: true }
console.log(g.return(1)); //{ value: undefined, done: true }

2.5 Generator.prototype.throw()

thorw()方法，通過拋出一個(gè)異常到迭代器中，來重新獲得迭代器的執(zhí)行；

返回帶有 value和done兩個(gè)屬性的object對(duì)象

function* gen() {
while(true) {
try {
yield 42;
} catch(e) {
console.log("Error caught!");
}
}
}
var g = gen();
var a = g.next();
// { value: 42, done: false }
var b = g.throw(new Error("Something went wrong"));
// "Error caught!"
// { value: 42, done: false }
console.log(a);
console.log(b.value+"::"+b.done);

以上所述是小編給大家介紹的JavaScript中 ES6 generator數(shù)據(jù)類型詳解，希望對(duì)大家有所幫助，如果大家有任何疑問請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)腳本之家網(wǎng)站的支持！

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