如何在 TypeScript 中检查数组是否包含字符串? [英] How do I check whether an array contains a string in TypeScript?

问题描述

目前我使用的是 Angular 2.0.我有一个数组如下:

Currently I am using Angular 2.0. I have an array as follows:

var channelArray: Array<string> = ['one', 'two', 'three'];

如何在 TypeScript 中检查 channelArray 是否包含字符串 'three'?

How can I check in TypeScript whether the channelArray contains a string 'three'?

推荐答案

与在 JavaScript 中相同，使用 Array.prototype.indexOf():

The same as in JavaScript, using Array.prototype.indexOf():

console.log(channelArray.indexOf('three') > -1);

或者使用 ECMAScript 2016 Array.prototype.includes():

Or using ECMAScript 2016 Array.prototype.includes():

console.log(channelArray.includes('three'));

<小时>

请注意，您还可以使用@Nitzan 所示的方法来查找字符串.但是，您通常不会对字符串数组执行此操作，而是针对对象数组执行此操作.那些方法更明智.例如

---

Note that you could also use methods like showed by @Nitzan to find a string. However you wouldn't usually do that for a string array, but rather for an array of objects. There those methods were more sensible. For example

const arr = [{foo: 'bar'}, {foo: 'bar'}, {foo: 'baz'}];
console.log(arr.find(e => e.foo === 'bar')); // {foo: 'bar'} (first match)
console.log(arr.some(e => e.foo === 'bar')); // true
console.log(arr.filter(e => e.foo === 'bar')); // [{foo: 'bar'}, {foo: 'bar'}]

参考

Array.find()

Array.some()

Array.filter()

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