Let's understand the concept of call by reference by the help of examples. variable $str is passed to the adder function where it is concatenated with 'Call By Reference' string.
Switch statement is used to execute one statement from multiple conditions in PHP. It works like PHP if-else-if statement. But it's better that if-else-if statement.
Simple way to create arrow in your HTML page, just add few line of CSS and create it. There two step to add arrow in your page.