javascript - 如何检查数组中是否包含TypeScript中的字符串？(How do I check whether an array contains a string in TypeScript?)

Question

Currently I am using Angular 2.0.(目前我正在使用Angular 2.0。)

I have an array as follows:(我有一个数组如下：) var channelArray: Array<string> = ['one', 'two', 'three']; How can I check in TypeScript whether the channelArray contains a string 'three'?(如何在TypeScript中检查channelArray是否包含字符串'three'？)   ask by code1 translate from so

Answer 1

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

console.log(channelArray.indexOf('three') > -1); Or using ECMAScript 2016 Array.prototype.includes() :(或者使用ECMAScript 2016 Array.prototype.includes（） ：) console.log(channelArray.includes('three')); Note that you could also use methods like showed by @Nitzan to find a string.(请注意，您还可以使用@Nitzan显示的方法来查找字符串。) However you wouldn't usually do that for a string array, but rather for an array of objects.(但是，对于字符串数组，通常不会这样做，而是对于一个对象数组。) There those methods were more sensible.(那些方法更明智。) For example(例如) 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'}] Reference(参考) Array.find()(Array.find（）) Array.some()(Array.some（）) Array.filter()(Array.filter（）)