js在数组中查找是否存在某一个数值

Posted 2021-11-03 gqx-html

目前想到的方法有这么几个

1.indexOf()  -> ES5

const array = [‘apple‘, ‘banance‘, ‘orange‘]

array.indexOf(‘apple‘)    // 0 存在

array.indexOf(‘strawBerry‘)     // -1不存在

 

2.find()   -> ES6

const array = [‘apple‘, ‘banance‘, ‘orange‘]

array.find(obj => obj == ‘banance‘)    //banance 存在

array.find(obj => obj == ‘strawBally‘)    //undefined 不存在

 

const arrayList = [

　　{name: ‘张三‘}， {name: ‘李四‘}

]

arrayList.find(obj => obj.name == ‘李四‘)        //{name: ‘李四‘} 存在

arrayList.find(obj => obj.name == ‘王五‘)        //undefined 不存在

 

3.findIndex()  -> ES6

const array = [‘apple‘, ‘banance‘, ‘orange‘]

array.findIndex(obj => obj == ‘banance‘)    //大于0存在

array.findIndex(obj => obj == ‘strawBally‘)    //-1 不存在

 

3.includes()

const array = [‘apple‘, ‘banance‘, ‘orange‘]

array.includes(‘banance‘)      //true存在

array.includes(‘strawBally‘)      //false存在

 

4.filter()

const array = [‘apple‘, ‘banance‘, ‘orange‘]

array.filter(obj => obj == ‘orange‘)     //[‘orange‘] 存在

array.filter(obj => obj == ‘strawBally‘)     //[] 不存在

 

const array = [{ name: ‘banance‘ }, { name: ‘apple‘ }]

console.log(array.filter(obj => obj.name === ‘apple‘))    //[{name: ‘apple‘}] 存在

console.log(array.filter(obj => obj.name === ‘strawBally‘))    //[] 不存在