JavaScript参考手册
发生器 | Generator
generator.throw
The throw()
method resumes the execution of a generator by throwing an error into it and returns an object with two properties done
and value
.
Syntax
gen.throw(exception)
Parameters
exception
The exception to throw. For debugging purposes, it is useful to make it an instanceofError
.
Return value
An Object
with two properties:
-
done
(boolean)- Has the value
true
if the iterator is past the end of the iterated sequence. In this casevalue
optionally specifies the return value of the iterator. - Has the value
false
if the iterator was able to produce the next value in the sequence. This is equivalent of not specifying thedone
property altogether.
- Has the value
-
value
- any JavaScript value returned by the iterator. Can be omitted whendone
istrue
.
Examples
Using throw()
The following example shows a simple generator and an error that is thrown using the throw
method. An error can be caught by a try...catch
block as usual.
function* gen() {
while(true) {
try {
yield 42;
} catch(e) {
console.log('Error caught!');
}
}
}
var g = gen();
g.next();
// { value: 42, done: false }
g.throw(new Error('Something went wrong'));
// "Error caught!"
// { value: 42, done: false }
Specifications
Specification |
Status |
Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262)The definition of 'Generator.prototype.throw' in that specification. |
Standard |
Initial definition. |
ECMAScript Latest Draft (ECMA-262)The definition of 'Generator.prototype.throw' in that specification. |
Draft |
|
Browser compatibility
Feature |
Chrome |
Edge |
Firefox (Gecko) |
Internet Explorer |
Opera |
Safari |
---|---|---|---|---|---|---|
Basic support |
(Yes) |
13 |
26 (26) |
No support |
(Yes) |
10 |
Feature |
Android |
Chrome for Android |
Edge |
Firefox Mobile (Gecko) |
IE Mobile |
Opera Mobile |
Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support |
5.1 |
(Yes) |
(Yes) |
26.0 (26) |
? |
? |
10 |
See also
function*
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Generator/throw
发生器 | Generator相关
JavaScript 是一种高级编程语言,通过解释执行,是一门动态类型,面向对象(基于原型)的解释型语言。它已经由ECMA(欧洲电脑制造商协会)通过 ECMAScript 实现语言的标准化。它被世界上的绝大多数网站所使用,也被世界主流浏览器( Chrome、IE、FireFox、Safari、Opera )支持。JavaScript 是一门基于原型、函数先行的语言,是一门多范式的语言,它支持面向对象编程,命令式编程,以及函数式编程。它提供语法来操控文本、数组、日期以及正则表达式等,不支持 I/O,比如网络