编辑代码

// String.prototype.trim = function () {
//     return this.replace(/^\s\s*/,'').replace(/\s\s*$/,'')
// }

String.prototype.trim = function () {
    return this.substring(Math.max(this.search(/^\S/),0),this.search(/\S\s*$/) + 1)
}
let str = '   a1ve  '

console.log(str.trim())

function trim(str) {
    return str.replace(/^\s\s*/,'').replace(/\s\s*$/,'');
}

console.log(trim('       123..   '))