JavaScript实现 trim

<!-- lang: js -->
String.prototype.trim = function() {
    return this.replace(/(^\s*)|(\s*$)/g, "");
};
String.prototype.ltrim = function() {
    return this.replace(/(^\s*)/g, "");
};
String.prototype.rtrim = function() {
    return this.replace(/(\s*$)/g, "");
};

function trim(str){ 
    return str.replace(/(^\s*)|(\s*$)/g, "");
}
function ltrim(str){ 
    return str.replace(/(^\s*)/g,"");
}
function rtrim(str){
    return str.replace(/(\s*$)/g,"");
}