Question: What is the best way to check if a single character is a whitespace?

I know how to check this through a regex.

But I am not sure if this is the best way if I only have a single character.

Isn't there a better way (concerning performance) for checking if it's a whitespace?

If I do something like this. I would miss white spaces like tabs I guess?

```
if (ch == ' ') {
    ...
}

```

Answer: 
```
var testWhite = (x) {
    var white = new RegExp(/^\s$/);
    return white.test(x.charAt(0));
};

```

This small function will allow you to enter a string of variable length as an argument and it will report "true" if the first character is white space or "false" otherwise. You can easily put any character from a string into the function using the indexOf or charAt methods. Examples:

```
var str = "Today I wish I were not in Afghanistan.";
testWhite(str.charAt(9));  // This would test character "i" and would return false.
testWhite(str.charAt(str.indexOf("I") + 1));  // This would return true.

```
how about this one :
((1L << ch) & ((ch - 64) >> 31) & 0x100002600L) != 0L