JS 数组删除指定元素以及数组排序

lfl183261621602024-06-30 0:07

删除

function cut(value) {

return value.slice(0,value.length-1)

}

排序

let arr = $5,2,1,4,9,8$ for(let i = 0 ; i < arr.length ; i ++) { for(let j = 0 ; j < arr.length -1 ; j ++) { if(arr $j$ > arr $j+1$ ){ let num = arr $j$ arr $j$ = arr $j+1$ arr $j+1$ = num comeout.innerText = arr } }

复制代码

// 升序
 arr.sort(function(a,b){
                return a - b
            })
         console.log(arr)
// 结果 1,2,4,5,8,9


// 降序
arr.sort(function(a,b){
                return b - a
            })
          console.log(arr)
// 结果 9,8,5,4,2,1

复制代码

let arr_choice = [{id:1},{id:3},{id:2},{id:8},{id:6},{id:4}]
// 升序
arr_choice.sort(function(a,b){
                return b.id - a.id
            })
          console.log(arr_choice)
// 结果：[{"id":1},{"id":2},{"id":3},{"id":4},{"id":6},{"id":8}]
   
         
// 降序
arr_choice.sort(function(a,b){
                return b.id - a.id
            })
         console.log(arr_choice)
// 结果：[{"id":8},{"id":6},{"id":4},{"id":3},{"id":2},{"id":1}]

复制代码

let arr_multi = [{id:1,age:10},{id:3,age:5},{id:2,age:6},{id:8,age:8},{id:6,age:5},{id:4,age:5}]
// 升序
arr_multi.sort(function(a,b){
                // 默认根据年龄排序，年龄相同则按照id排序
                if(a.age==b.age){
                    return a.id - b.id
                }
                return a.age - b.age
            })
      console.log(arr_multi)
// 结果：[{"id":3,"age":5},{"id":4,"age":5},{"id":6,"age":5},{"id":2,"age":6},{"id":8,"age":8},{"id":1,"age":10}]
         

// 降序
 arr_multi.sort(function(a,b){
                // 默认根据年龄排序，相同则按照id排序
                if(a.age==b.age){
                    return b.id - a.id 
                }
                return b.age - a.age 
            })
            console.log(arr_multi)
// 结果：[{"id":1,"age":10},{"id":8,"age":8},{"id":2,"age":6},{"id":6,"age":5},{"id":4,"age":5},{"id":3,"age":5}]