JS determines whether it is a number, whether it is an integer, or whether it is a floating-point code

Function checkrate (input)
{
var re =/^[0-9]+.? [0-9]*$/; Determines whether a string is a number//judgment positive integer/^[1-9]+[0-9]*]*$/
if (!re.test (input.rate.value))
{
Alert ("Please enter a number (for example: 0.02)");
Input.rate.focus ();
return false;
}
}

The following is a normal function
to copy the code as follows:
function Baseisnotnum (thenum)
{
//judge whether the number
if (Basetrim (thenum) = "")
return true;
for (Var i=0;i<thenum.length;i++) {
onenum=thenum.substring (i,i+1);
if (onenum< "0" | | | onenum> "9")
return true;
}
return false;
}
Function Baseisnotint (theint)
{
//To determine whether it is an integer
Theint=basetrim (Theint);
if (theint.length>1 && theint.substring (0,1) = = "0") | | Baseisnotnum (Theint)) {
return true;
}
return false;
}
Function Baseisnotfloat (thefloat)
{
//determine if floating-point number
Len=thefloat.length;
Dotnum=0;
if (len==0)
return true;
for (Var i=0;i<len;i++) {
onenum=thefloat.substring (i,i+1);
if (onenum==.)
dotnum++;
if ((onenum< "0" | | | onenum> "9") && onenum!= ".") | | DOTNUM>1)
return true;
}
if (len>1 && thefloat.substring (0,1) = = "0") {
if (thefloat.substring (1,2)!= ".")
RetuRN true;
}
return false;