To prevent this behavior it is sufficient to add an unset($value) statement after each loop where it is used. More info here: PHP: Passing by Reference It's very confusing, but it's not even slightly idiosyncratic it's the code executing exactly as it should. So in the 3rd iteration of the second loop, $value and $variable become equal to 4 by reference, then during the 4th and final iteration of the second loop, nothing changes because you're passing the value of $variable (which is still &$value) to $value (which is still &$value). With each evaluation of this foreach, both $value and $variable are becoming equal to the value of the iterable item in $variable. Both are described below.At the end of the first loop, $value is pointing to the same place as $variable ( they are pointing to the same location in memory): $variable = Įven as this loop is finished, $value is still a reference that's pointing to the same location in memory as $variable, so each time you store a value in $value, this also overwrites the value stored for $variable: foreach ($variable as $key => $value) After that, looping through the array elements along with performing some action by using the foreach loop.Īlso, note that you can use the foreach loop with array or objects only.Īs described in the first section, there are two ways to use the foreach loop in PHP. For example, fetching multiple rows from a table of MySQL database and assigning it to an array. If you work with MySQL or some other database, then its purpose will be even clearer. However, foreach makes it quite simpler which is specifically provided to use with arrays. by using the length property to get the length of the array and then using it as the max operator. You can also use a simple for loop to manipulate arrays e.g. The foreach loop works only on arrays, and is used to loop through each key/value pair in an array. The foreach will loop through each element of the given array. The PHP foreach loop is used to manipulate arrays. See online demo and code Why we use PHP foreach? See the demo and code by clicking the link or image below: To see the difference between array before and after assigning the new values, the array is displayed by using the print_r function, which is used to display the visual representation of the given array. Inside curly braces, we assigned new values to the array elements. Then we simply used a foreach loop to display array element values.Īfter that, we used another foreach loop where the $value_of_element is preceded by “&”. In this example, we have created a numeric array of five elements. To make it clearer, see the following example. For that, use the “&” before the “$” for the value variable e.g. You can modify the values of the elements of the given array by using the foreach loop. See online demo and code An example to change array element values in foreach loop The $salaries array is defined followed by three employee names (acting as keys) and salaries as values. For that, we have created an associative array of three elements. In this example, we will use the other way of using the foreach loop i.e. See online demo and code An example with array key and values See the example and code by clicking the image or link below: Inside the foreach loop, we used echo statement to display the array values. After that, a foreach PHP loop is used to iterate through that array. In this example, we have created an array of five elements with numeric values. Both of these methods of using foreach are explained in the last part of this tutorial, after the examples below.Įxample of using foreach loop with numeric array
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