In PHP, this function is used to compare two strings and is case sensitive.

    strcmp(string1,string2)

In the above syntax "string1", "string2" specifies the strings to be compared, the function returns "0" if both strings are equal, returns a value ">0" if "string1" is greater than "string2", returns a value "<0" if "string1" is less than "string2".

    <?php
    $s1="Hello World";
    $s2="hello world";
    echo strcmp($s1,$s2);
    echo "<br>";
    if(strcmp($s1,$s2)==0)
      {
      echo "Two strings are matching";
      }
    else
      {
      echo "Two strings are different";
      }
    ?>

    -1
    Two strings are different 

In the above string example if we have used strcasecmp(), it will give a result "0",ie., both strings are equal, but when used strcmp() as its case sensitive it gives a result "-1",ie., "string1" is less than "string2".