js對字符串的順序截取

截取字符串前幾位

var disName =‘123456’;
var shortName = disName.substring(0,5);
console.log(shortName);//打印結果：12345

截取字符串後幾位

var disName =‘54321’;
var disLength = disName.length;
var shortName = disName.substring(disLength-2,disLength);
console.log(shortName);//打印結果：21