single quote inside double quote in php

Question

In the project,the above code need to be put into String(see 2nd snippet). However,

Answer 1

Alternatively

$string = '<input id="myID" onClick="CheckAll(\'A\',\'B\');" />';

Answer 2

$string ="<input id='myID' onClick=\"CheckAll('A','B');\" />"

add escaping slashes

Answer 3

You can use backslash:

$string ="<input id=\"myID\" onClick=\"CheckAll('A','B');\" />"