(PHP 4, PHP 5)
is_numeric — Finds whether a variable is a number or a numeric string
Finds whether the given variable is numeric. Numeric strings consist of optional sign, any number of digits, optional decimal part and optional exponential part. Thus +0123.45e6 is a valid numeric value. Hexadecimal notation (0xFF) is allowed too but only without sign, decimal and exponential part.
The variable being evaluated.
Returns TRUE if var is a number or a numeric string, FALSE otherwise.