js

let answers=[];

 answers=answers.concat(data.list);     // 数组连接

// 通过数组中元素的某个字段排序：

this.answerInfo = answers.sort((t1,t2)=>{

       return t1.questionIndex-t2.questionIndex;

     });

 

删除数组索引是 i 的 元素： arr.splice(i,1)  

var arr = new Array(6)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
arr[3] = "James"
arr[4] = "Adrew"
arr[5] = "Martin"

arr.splice(3,1)
console.log(arr)

输出： 
[ 'George', 'John', 'Thomas', 'Adrew', 'Martin' ]

 三： 数组 filter 

let answer = [];
let answerText = "";
let add = {
    answerText: ""
};

add.answerText = "A,C";
if (add.answerText) {
    answerText = add.answerText.split(",");
    console.log(add.answerText)
    console.log(answerText)
    answerText.filter((item) => {
        answer.push({ text: item });
    });
    console.log(answer)
}


输出： 
A,C
[ 'A', 'C' ]
[ { text: 'A' }, { text: 'C' } ]

四： 获取文件名：

let file="www.baidu.com/test/abc.jpg"
let filename=file.substr(file.lastIndexOf("/")+1)
console.log(filename)

输出：
abc.jpg

五： 数组去重：

var temp = ["grade.1", "grade.2","grade.1"]

var uniArr = uniqueArr(temp)

console.log(uniArr)                   // 输出 ["grade.1", "grade.2"]

function uniqueArr(arr) {
return Array.from(new Set(arr))
}

六： 排序：

var temp = [1, 3,4,2]

temp.sort(function(a, b){return a - b});