<!DOCTYPE html><html><head><meta charset="UTF-8"><title>格式化数字</title></head><body><script type="text/javascript">/**方法一 不加千分位（整数部分最大15位，小数为最多4位）object --文本框对象n --保留的小数位*/function fmoney(object,n){ ???// ^-?[0-9]+\.?[0-9]*$ 验证浮点数 ???var num = ?object.value; ???var start = num.indexOf(‘-‘); ???if(start == 0){ ???????num = num.substring(1,15); ???}else{ ???????num = num.substring(0,15); ???} ???num = parseFloat((num + "").replace(/[^\d\.-]/g, "")).toFixed(n) + ""; ??????if (isNaN(num) || ((num + "").replace(/\s/g, "")) == "") { ???????object.value = ""; ???????return; ???} ???n = n > 0 && n <= 20 ? n : 2; ??????var l = num.split(".")[0].split("").reverse(),r = num.split(".")[1],t = ""; ??????for(var i = 0; i < l.length; i ++ ){ ????????//t += l[i] + ((i + 1) % 3 == 0 && (i + 1) != l.length ? "," : ""); //加千分位 ???????t += l[i]; ??????} ??????if(start == 0){ ???????object.value = "-"+t.split("").reverse().join("") + "." + r; ???}else{ ???????object.value = t.split("").reverse().join("") + "." + r; ???}} ??/**方法二 加千分位 （整数部分最大15位）object --文本框对象n --保留的小数位*/function simpleFormat(object,n){ ???var num = object.value; ???num = num.substring(0,15); ???num = parseFloat((num + "").replace(/[^\d\.-]/g, "")).toFixed(n)+""; ??????if (isNaN(num) || ((num + "").replace(/\s/g, "")) == "") { ???????object.value = ""; ???????return; ???} ???object.value = num; ???var value = num.replace(/(\d)(?=(\d{3})+(?!\d))/g, "$1,") ?????object.value = value;}function rmoney(s){ ?????return parseFloat(s.replace(/[^\d\.-]/g, "")); ??}</script><input type="text" id="11" style="width:200px" onblur=‘fmoney(this,4)‘/><input type="button" value="还原" onclick="r11()"><br><input type="text" id="33" style="width:200px" onblur=‘simpleFormat(this,4)‘/><input type="button" value="还原" onclick="r33()"><script type="text/javascript">function r11(){ ???var value = document.getElementById("11").value; ???alert(rmoney(value));}function r33(){ ???var value = document.getElementById("33").value; ???alert(rmoney(value));}</script></body></html>js格式化数字
原文地址：http://www.cnblogs.com/bunuo/p/7611195.html