//加法
function add(a, b) {
var c, d, e;
try{
c = a.toString().split(".")[1].length;
}catch(f) {
c = 0;
}
try{
d = b.toString().split(".")[1].length;
}catch(f) {
d = 0;
}
return e = Math.pow(10, Math.max(c, d)), (mul(a, e) + mul(b, e)) / e;
}
//减法前边减后边
function sub(a, b) {
var c, d, e;
try{
c = a.toString().split(".")[1].length;
}catch(f) {
c = 0;
}
try{
d = b.toString().split(".")[1].length;
}catch(f) {
d = 0;
}
return e = Math.pow(10, Math.max(c, d)), (mul(a, e) - mul(b, e)) / e;
}
//除法
function div(a, b) {
var c, d, e = 0,
f = 0;
try{
e = a.toString().split(".")[1].length;
}catch(g) {}
try{
f = b.toString().split(".")[1].length;
}catch(g) {}
return c = Number(a.toString().replace(".","")), d = Number(b.toString().replace(".","")), mul(c / d, Math.pow(10, f - e));
}
//乘法
function mul(a, b) {
var c = 0,
d = a.toString(),
e = b.toString();
try{
c += d.split(".")[1].length;
}catch(f) {}
try{
c += e.split(".")[1].length;
}catch(f) {}
return Number(d.replace(".","")) * Number(e.replace(".","")) / Math.pow(10, c);
}
