How to automatically add ',' to numbers in PHP?

So that 335000 开发者_JS百科become 335,000?

You can use the number_format function :

$number = 335000;
echo number_format($number);

Will get you :

335,000

And, if necessary, you can use the additionnal parameters (see the manual page) to use a different number of digits, another decimal separator, ...