在js中对数字进行加减，保留小数

1.两个数字相加

function accAdd(arg1, arg2) { var r1, r2, m, c; try { r1 = arg1.toString().split(".")[1].length; } catch (e) { r1 = 0; } try { r2 = arg2.toString().split(".")[1].length; } catch (e) { r2 = 0; } c = Math.abs(r1 - r2); m = Math.pow(10, Math.max(r1, r2)); if (c > 0) { var cm = Math.pow(10, c); if (r1 > r2) { arg1 = Number(arg1.toString().replace(".", "")); arg2 = Number(arg2.toString().replace(".", "")) * cm; } else { arg1 = Number(arg1.toString().replace(".", "")) * cm; arg2 = Number(arg2.toString().replace(".", "")); } } else { arg1 = Number(arg1.toString().replace(".", "")); arg2 = Number(arg2.toString().replace(".", "")); } return (arg1 + arg2) / m; }

2.两个数字相减

function accReduce(arg1, arg2) { var r1, r2, m, c; try { r1 = arg1.toString().split(".")[1].length; } catch (e) { r1 = 0; } try { r2 = arg2.toString().split(".")[1].length; } catch (e) { r2 = 0; } c = Math.abs(r1 - r2); m = Math.pow(10, Math.max(r1, r2)); if (c > 0) { var cm = Math.pow(10, c); if (r1 > r2) { arg1 = Number(arg1.toString().replace(".", "")); arg2 = Number(arg2.toString().replace(".", "")) * cm; } else { arg1 = Number(arg1.toString().replace(".", "")) * cm; arg2 = Number(arg2.toString().replace(".", "")); } } else { arg1 = Number(arg1.toString().replace(".", "")); arg2 = Number(arg2.toString().replace(".", "")); } return (arg1 - arg2) / m; }

3.保留小数

function NumRound(value, n) { // 取某个数的平方，如： Math.pow(10,2)：100 //value:数字 n:保留几位 return Math.round(value * Math.pow(10, n)) / Math.pow(10, n); }

4.去掉字符串前几个字符

var name="aaaxiaohei"; name.slice(3);//name="xiaohei"

5.去掉字符串后几个字符

var name="xiaoheiaaa"; name.substring(0, date.length-3);//name="xiaohei"

6.取绝对值

Math.abs(-1);//值为1