for Number

github: https://github.com/laixiangran/commonJS/blob/master/src/forNumber.js

代码

/**

 * Created by laixiangran on 2016/1/24

 * homepage：http://www.cnblogs.com/laixiangran/

 * for Number

 */

(function(undefined) {

    var com = window.COM = window.COM || {};

    com.$N = {

        // 数字保留n位小数，返回数字

        toFixedReturnNumber: function(num, n) {

            return Number(num.toFixed(n));

        },

        // 提取数字中的整数部分

        integer: function(num) {

            // Math.ceil 向上舍入，Math.floor 向下舍入

            return Math[num < 0 ? "ceil" : "floor"](this);

        }

    };

}());

参考

http://www.cnblogs.com/cloudgamer/