How to Find if a String Contains a Word in PHP

John on January 25, 2021

The strpos() function finds the first occurrence of a string inside another string in PHP. It is a case-sensitive function that returns the index of the first character of a string if a match is found and false if no matches are found.

Let's try out a basic example of looking for a string in a string using strpos():

$str = 'This is some text.';

$result = strpos($str, 'some');

print_r($result);

8

As expected strpos() returns 8 as the position of the substring "some" in the example above.

strpos() can be used to check whether a string contains a specific word and do something as a result with a conditional if statement:

$str = 'This is some text.';

$result = strpos($str, 'text');

if ($result !== false) {
  print_r($result);
} else {
  print_r('No result do something else.');
}

13

Set a Start Position for strpos()

An optional third argument can be used with strpos() to specify an index to begin searching from.

$str = 'This is some text.';

$result = strpos($str, 'This', 8);

if ($result !== false) {
  print_r($result);
} else {
  print_r('No result do something else.');
}

No result do something else.

Conclusion

For old versions of PHP the stripos() function can be used to achieve the same results as strpos() though it is slower.