String.prototype.reverse = function() {

  var a = this.split('');

  for (var i = 0, j = a.length-1; i < j; i++, j--) {

    var tmp = a[i];

    a[i] = a[j];

    a[j] = tmp;

  }

  return a.join('');

}

// test

var s = "Hello world!";

console.log(s.reverse());

 // !dlrow olleH

// 去字符串#后面的部分  http://localhost:8090/admin/activity.html#list => list

String.prototype.hash = function() {

    var index = this.lastIndexOf("#");

    return index < 0 ? "" : this.substring(index);

};

// 字符串宽度 汉字算1个 英文字母数字算半个

String.prototype.width = function() {

    var c = 0, inc;

    for (var i = 0, n = this.length; i < n; i++) {

        inc = this.charCodeAt(i) < 256 ? 0.5 : 1;

        c += inc;

    }

    return c;

}

String.prototype.mb_substr = function(w) {

    var c = 0, inc, i;

    for (i = 0, n = this.length; i < n && c <= w; i++) {

        inc = this.charCodeAt(i) < 256 ? 0.5 : 1;

        c += inc;

    }

    return this.substring(0, i);

}

// 返回整数数组的最大值

Array.prototype.max = function() {

    var max = this[0];

    for (var i = 1, n = this.length; i < n; i++) {

        if (this[i] > max) {

            max = this[i];

        }

    }

    return max;

};

// 去掉html中的标签  <div><p>...

function strip_tags(html) {

    var div = document.createElement("div");

    div.innerHTML = html;

    return (div.textContent || div.innerText || "");

}

// 去的当前年月 201806

function get_yyyymm() {

    var date = new Date();

    var month = date.getMonth()+1;

    return (date.getYear() + 1900) + ""+ (month<10 ? "0"+month : month);

}

// 引入css(jquery-ui.css), 到head >link:first-child前

// load css before all <link> tags

function css(href) {

    var link = document.createElement("link");

    link.type = "text/css";

    link.rel = "stylesheet";

    link.href = href;

    var dom = document.head.querySelector("link");

    document.head.insertBefore(link, dom);

}

function strLength(s, bUnicode255For1) {

    var len = 0;

    for (var i = 0, n = s.length; i < n; i++) {

        if (s.charCodeAt(i) > 255) {

            len += bUnicode255For1 ? 1:2;

        } else {

            len += 1;

        }

    }

    return len;

}