js判断一个数组是否包含一个指定的值

今天看了一下有好几种方法总结一下

1：array.indexOf 此方法判断数组中是否存在某个值，如果存在返回数组元素的下标，否则返回-1

let arr = ['something', 'anything', 'nothing', 'anything'];

let index = arr.indexOf('nothing');

console.log(index) //结果是2

function test(fruit) {

const redFruits = ['apple', 'strawberry', 'cherry', 'cranberries'];

if (redFruits.includes(fruit)) {

console.log('red');

}else{

console.log('blue');

}

test('aple')//结果是red

// ---------- 元素是普通字面值 ----------

let numbers = [12, 5, 8, 130, 44];

let result = numbers.find(item => {

return item > 8;

});

console.log(result)

# 结果： 12

// ---------- 元素是对象 ----------

let items = [

{id: 1, name: 'something'},

{id: 2, name: 'anything'},

{id: 3, name: 'nothing'},

{id: 4, name: 'anything'}

];

let item = items.find(item => {

return item.id == 3;

});

console.log(item) # 结果： Object { id: 3, name: "nothing" }

from:https://www.cnblogs.com/hepengqiang/p/9822118.html