有时候觉得js内置的方法不够用.可自己扩充.
下面是我扩充的几个方法.
为了避免变量冲出.覆盖.利用自执行函数实现.
+function (a) {
a.fn = a.prototype;
var fn = {
/**
* 进制转换
* @param to
* @returns {string}
*/
toBits: function (to) {
var bits = [];
var t = this;
var i = 0;
for (i; i < t.length; i++) {
var code = t.charCodeAt(i);
bits.push(code.toString(to));
}
bits.reverse();
return bits.join("");
},
/**
* 去除右变指定字符串.默认空白
* @returns {XML|string|void|*}
*/
rtrim: function () {
var replace = arguments[0] || "\\s";
var r = new RegExp("(^" + replace + "{1,})");
return this.replace(r, '');
},
/**
* 去除左边指定字符串.默认空白
* @returns {XML|string|void|*}
*/
ltrim: function () {
var replace = arguments[0] || "\\s";
var r = new RegExp("(" + replace + "{1,}$)");
return this.replace(r, '');
},
/**
* 去除两边指定字符串.默认空白
* @returns {XML|string|void|*}
*/
trim: function () {
var str = this, a = arguments;
str = str.ltrim.apply(str.rtrim.apply(str, a), a);
return str;
},
str_repeat: function (i, m) {
for (var o = []; m > 0; o[--m] = i);
return o.join('');
},
/**
* c的sprintf实现
* @returns {string}
*/
sprintf: function () {
var i = 0, a, f = this.toString(), o = [], m, p, c, x, s = '';
while (f) {
if (m = /^[^\x25]+/.exec(f)) {
o.push(m[0]);
}
else if (m = /^\x25{2}/.exec(f)) {
o.push('%');
}
else if (m = /^\x25(?:(\d+)\$)?(\+)?(0|'[^$])?(-)?(\d+)?(?:\.(\d+))?([b-fosuxX])/.exec(f)) {
if (((a = arguments[m[1] || i++]) == null) || (a == undefined)) {
throw('Too few arguments.');
}
if (/[^s]/.test(m[7]) && (typeof(a) != 'number')) {
throw('Expecting number but found ' + typeof(a));
}
switch (m[7]) {
case 'b':a = a.toString(2);break;
case 'c':a = this.fromCharCode(a); break;
case 'd':a = parseInt(a);break;
case 'e':a = m[6] ? a.toExponential(m[6]) : a.toExponential(); break;
case 'f':a = m[6] ? parseFloat(a).toFixed(m[6]) : parseFloat(a);break;
case 'o':a = a.toString(8);break;
case 's':a = ((a = String(a)) && m[6] ? a.substring(0, m[6]) : a);break;
case 'u':a = Math.abs(a);break;
case 'x':a = a.toString(16); break;
case 'X':a = a.toString(16).toUpperCase();break;
}
a = (/[def]/.test(m[7]) && m[2] && a >= 0 ? '+' + a : a);
c = m[3] ? m[3] == '0' ? '0' : m[3].charAt(1) : ' ';
x = m[5] - String(a).length - s.length;
p = m[5] ? this.str_repeat(c, x) : '';
o.push(s + (m[4] ? a + p : p + a));
}
else {
throw('Huh ?!');
}
f = f.substring(m[0].length);
}
return o.join('');
}
};
for (var i in fn) {
a.fn[i] = fn[i];
}
window.String = a;
}(String);