## 例

`

     bool is_numeric ( mixed $var )

`

## 説明

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.

## 戻り値

Returns TRUE if var is a number or a numeric string, FALSE otherwise.