How Does PHP Compare Strings With Comparison Operators

PHP will compare alpha strings using the greater than and less than comparison operators based up on alphabetical order.

Example:

/* In alphabetic The order is like this :
            a b c d e .....
so order is 1 2 3 4 5
b greater than a and d greater than b ....
*/ 
if('a'>'b'){
    echo 'yes';
}
else{
    echo 'no';
}

// Output : no