String OperatorsPHP ManualPrevChapter 10. OperatorsNextString Operators There are two string operators. The first is the concatenation operator ('.'), which returns the concatenation of its right and left arguments. The second is the concatenating assignment operator ('.='). Please read Assignment Operators for more information. 1  2 $a = "Hello "; 3 $b = $a . "World!"; // now $b contains "Hello World!" 4  5 $a = "Hello "; 6 $a .= "World!"; // now $a contains "Hello World!" 7  PrevHomeNextOperator PrecedenceUpControl Structures