This is an example why pass-by-reference in foreach loops is BAD. Do not use return-by-reference to increase performance. Passing a variable by reference or by value to a function is a very useful concept for PHP programmers. @pinusnegra Read first line: "I'm just trying to understand passing by reference in PHP by trying some examples found on php.net." In PHP generally, we followed to pass the arguments to the function with passed by value approach. How to pass PHP Variables by reference ? PHP – Pass by Reference or Pass by Value. In PHP, arguments are usually passed by value, which means that a copy of the value is used in the function and the variable that was passed into the function cannot be changed. ... after the pass-by-reference loop. Teams. For some PHP versions, pass by reference concept doesn’t work well. Last Updated : 20 Dec, 2018; By default, PHP variables are passed by value as the function arguments in PHP. The engine will automatically optimize this on its own. When variables in PHP is passed by value, the scope of the variable defined at function level bound within the scope of function. By default, objects are passed by value. Only return references when you have a … Clearly, PHP, like C++, is a language that does support pass by reference. When a function argument is passed by reference, changes to the argument also change the variable that was passed in. Pass By Reference vs. – Frederik Wordenskjold Jan 14 '12 at 15:46. add a comment | 6 Answers Active Oldest Votes. Call-time pass-by-reference has been deprecated - argument passed by value; If you would like to pass it by reference, modify the declaration of xxxxx. However, future versions may not support this any longer I wrote an extensive, detailed blog post on this subject for JavaScript, but I believe it applies equally well to PHP, C++, and any other language where people seem to be confused about pass by value vs. pass by reference. Passing Arguments by Reference. In this article, we will learn about pass by value and pass by reference in PHP. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Normally, when you are passing a variable to a functon, you are passing “by value” which meand the PHP procesor will make a duplicate variable to work on. Now, let’s understand these two concepts in detail. So, if you ever were to use this coding style, don't forget to unset the reference … Q&A for Work. 6. If you would like to enable call-time pass-by-reference, you can set allow_call_time_pass_reference to true in your INI file. PHP foreach pass-by-reference: Do it right, or better not at all. Pass By Value Reference Variables. Returning by reference is useful when you want to use a function to find to which variable a reference should be bound. A reference variable is a nickname, or alias, for some other variable; To delare a reference variable, we use the unary operator & int n = 5; // this declares a variable, n int & r = n; // this declares r as a reference to n In this example, r is now a reference to n. #php. In this way, the PHP pass by reference concept works and it is an important concept to know at some of the coding cases. Your code and the example code is not the same.