Use of undefined constant VIEWPATH issue occurs when you upgrade your existing CodeIgniter application version to CodeIgniter 3.x. The undefined constant viewpath issue can be easily solved by the following solution. Open the root’s index.php file and specify the view directory to solve this issue.
Code optimization can reduce the execution time of the script. Using the looping statements, you can get an array of a specific key from the multidimensional array. But the same work can be done in a single line of code by array_column() function in PHP.
You can access two types of value from select element. First one is the value to be sent to the server, which can easily get using the jQuery. The second one is the text value of the select element. Based on your requirement, single or both values can get from the select element.
Most of the cases the value of selected radio button gets after form submit. But if you want to get the value of selected radio button before form submits, with jQuery you can do it easily. The jQuery :checked selector helps to get the value of selected radio button.
PHP array_filter() function filters elements of an array by a callback function and it can be used for many purposes. The array_filter() function provides a short and simple way to filter multidimensional array by key and value. Use array_filter() to filter values from multidimensional array similar to SQL LIKE using array_filter() function in PHP.