A number of ways to compare string with PHP, used in the post http://www.paulund.co.uk/how-to-compare-strings-in-php

compare-strings-with-double-equals-capitals.php

<?php
// Using the == operator, Strings do not match is printed
if('string1' == 'STRING1')
{
    echo 'Strings match.';
} else {
    echo 'Strings do not match.';
}

compare-strings-with-double-equals.php

<?php
// Using the == operator, Strings match is printed
if('string1' == 'string1')
{
    echo 'Strings match.';
} else {
    echo 'Strings do not match.';
}

compare-strings-with-strcasecmp.php

<?php
// Both strings will match
if(strcasecmp('string1', 'string1') == 0)
{
     echo 'Strings match.';
} else {
     echo 'Strings do not match.';
}

// Both strings will match even with different case
if(strcasecmp('string1', 'String1') == 0)
{
     echo 'Strings match.';
} else {
     echo 'Strings do not match.';
}

// Both strings will match even with different case
if(strcasecmp('string1', 'STRING1') == 0)
{
     echo 'Strings match.';
} else {
     echo 'Strings do not match.';
}

compare-strings-with-strcmp.php

<?php
// strcmp function, Strings match is printed
if(strcmp('string1', 'string1') == 0)
{
     echo 'Strings match.';
} else {
     echo 'Strings do not match.';
}