.slice()取指定位置的值

let array = ["A","R","R","A","Y"];
array = array.slice(2);//array = ["R","A","Y"];
array = array.slice(-2);//array = ["Y","A"];

let phone = "18136985214";
phone = phone.slice(3,7);//索引從0開始 排除手機号前3位和後四位 傳回中間的數字 phone= 3698;