JavaScript中的数组

by xu xiaofei

JavaScript

let arr = [1,2,3,4,5];
let arr2 = arr.slice(1,3);
//console.log(arr)  //[ 1, 2, 3, 4, 5 ]
//console.log(arr2) //[ 2, 3 ]

// arr.splice()
let arr3 = arr.splice(1,2,'m','n','p')
//console.log(arr);//[ 1, "m", "n", "p", 4, 5 ]
//console.log(arr3);//[ 2, 3 ]

let arr4 = arr.concat('abcd',[100,[101]]);
//console.log(arr)//[ 1, "m", "n", "p", 4, 5 ]
//console.log(arr4);// [ 1, "m", "n", "p", 4, 5, "abcd", 100, [101] ]

let str = arr.join('-')
console.log(arr)//[ 1, "m", "n", "p", 4, 5 ]
console.log(str)//1-m-n-p-4-5

let arr5 = arr.copyWithin(1,3,6)
console.log(arr) //[ 1, "p", 4, 5, 4, 5 ]
console.log(arr5) //[ 1, "p", 4, 5, 4, 5 ]

let arr6 = arr.reverse().reverse()
console.log(arr) //[ 5, 4, 5, 4, "p", 1 ]
console.log(arr6) //[ 5, 4, 5, 4, "p", 1 ]

let arr7 = arr.join()
console.log(arr) //[ 5, 4, 5, 4, "p", 1 ]
console.log(arr6) //[ 5, 4, 5, 4, "p", 1 ]