is_numeric

WMPRO, WMMINI FW >= 1.0 WMMEGA FW >= 2.0

Check if a value is numeric (int, float or numeric string)

Description

int is_numeric ( mixed $value )

Check to see if a value is numeric

Parameter

$value: Variable or expression to be evaluated

Return Values

Integer: 1 (true) if numeric, 0 (false) if not numeric (arrays always return 0)

Examples

<?
  $f=1.0;
  print(is_numeric($f));   // outputs 1, $f is a float
  $i=1;
  print(is_numeric($i));   // outputs 1, $i is an int
  $nns="cool";
  print(is_numeric($nns)); // outputs 0, $nns is a non-numeric string
  $ns="-1.5";
  print(is_numeric($ns));  // outputs 1, $ns is a numeric string
?>

Set up an array of different types of values, iterate through the array, output type, value and whether is_numeric() returns true or false

<pre><?
  $tests = array(
    1337,
    0x539,         // 1337 expressed in hexadecimal format
    02471,         // 1337 expressed in octal format
    0b10100111001, // 1337 expressed in binary format
    -25,
    42.8,
    -365.0,
    "42.9",
    "no numbers",
    "123 with numbers",
    array(1,2,3),
  );
  for ($i=0;$i<sizeof($tests);$i++) {
    if (is_int($tests[$i])) print("The int");
    if (is_float($tests[$i])) print("The float");
    if (is_string($tests[$i])) print("The string");
    if (is_array($tests[$i])) print("The array");
    if (!is_array($tests[$i])) print(" '".$tests[$i]."'");
    if (is_numeric($tests[$i])) {
      print(" is numeric\r\n");
    } else {
      print(" is NOT numeric\r\n");
    }
  }
?></pre>

The above example will output:

The int '1337' is numeric
The int '1337' is numeric
The int '1337' is numeric
The int '1337' is numeric
The int '-25' is numeric
The float '42.799999' is numeric
The float '-365.011138' is numeric
The string '42.9' is numeric
The string 'no numbers' is NOT numeric
The string '123 with numbers' is NOT numeric
The array is NOT numeric

Notes

Unlike functions is_int(), is_float(), is_string() and is_array() this function looks at more than just the type of the variable, it also checks strings to see if they are numeric.

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