how to check if a string contains only numbers in php code example

Example 1: php check if string or number

<?php if (is_numeric(887)) { echo "Yes"; } else { echo "No"; } ?>

Example 2: php check if string or number

<?php if (is_numeric("cake")) { echo "Yes"; } else { echo "No"; } ?>

Example 3: check if includes numbers php

if (preg_match('~[0-9]+~', $string)) {
    echo 'string with numbers';
}

Example 4: check value contains numbers or letters php

ctype_digit(string text);

Parameter Used:
The ctype_digit() function in PHP accepts only one parameter.

text : Its mandatory parameter which specifies the tested string.

Return Values:
It returns TRUE if all characters of the string are numeric otherwise 
  return FALSE.
  
Input  : '789495001'
Output : TRUE
Explanation : All digits, return True

Input  : 'adc123' or '789.0877'
Output : FALSE
Explanation: String contains number and string or floating point, 
return false.