<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
</head>
<body>
<script type="text/javascript">
/**
* 乘法
* @param arg1
* @param arg2
* @returns {Number}
*/
function accMul(arg1, arg2) {
var m = 0,
s1 = arg1.toString(),
s2 = arg2.toString();
try {
m += s1.split(".")[1].length
} catch(e) {}
try {
m += s2.split(".")[1].length
} catch(e) {}
return Number(s1.replace(".", "")) * Number(s2.replace(".", "")) / Math.pow(10, m)
}
/**
* 除法
* @param arg1
* @param arg2
* @returns {Number}
*/
function accDiv(arg1, arg2) {
var t1 = 0,
t2 = 0,
r1, r2;
try {
t1 = arg1.toString().split(".")[1].length
} catch(e) {}
try {
t2 = arg2.toString().split(".")[1].length
} catch(e) {}
with(Math) {
r1 = Number(arg1.toString().replace(".", ""))
r2 = Number(arg2.toString().replace(".", ""))
return(r1 / r2) * pow(10, t2 - t1);
}
}
/**
* 加法
* @param arg1
* @param arg2
* @returns {Number}
*/
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
}
/**
* 减法
* @param arg1
* @param arg2
* @returns
*/
function accSub(arg1, arg2) {
var r1, r2, m, n;
try {
r1 = arg1.toString().split(".")[1].length
} catch(e) {
r1 = 0
}
try {
r2 = arg2.toString().split(".")[1].length
} catch(e) {
r2 = 0
}
m = Math.pow(10, Math.max(r1, r2));
//last modify by deeka
//动态控制精度长度
n = (r1 >= r2) ? r1 : r2;
return((arg1 * m - arg2 * m) / m).toFixed(n);
}
console.log(accMul(7.88, 0.8) + ‘--7.88*0.8------乘法‘); //乘法
console.log(accDiv(7.88, 0.8) + ‘--7.88/0.8------除法‘); //除法
console.log(accAdd(7.88, 0.8) + ‘--7.88+0.8------加法‘); //加法
console.log(accSub(7.88, 0.8) + ‘--7.88-0.8------减法‘); //减法
</script>
</body>
</html>
复制代码封装起来 引入直接调用
原文：https://www.cnblogs.com/1212dsa/p/11428708.html