Q:
How to check whether a variable is set or not in PHP
belongs to collection: PHP and MySQL Frequently Asked Questions
PHP and MySQL Frequently Asked Questions
- How to write comments in PHP
- How to remove white space from a string in PHP
- How to find number of characters in a string in PHP
- How to find the number of words in a string in PHP
- How to remove HTML special characters from a string in PHP
- How to prepend a string in PHP
- How append a string in PHP
- How to extract substring from a string in PHP
- How to compare two strings in PHP
- How to get current page URL in PHP
- How to create a string by joining the values of an array in PHP
- How to split a string into an array in PHP
- How to combine two strings in PHP
- How to convert a string to lowercase in PHP
- How to convert a string to uppercase in PHP
- How to convert the first letter of a string to uppercase in PHP
- How to convert special HTML entities back to characters in PHP
- How to remove white space from the beginning of a string in PHP
- How to remove white space from the end of a string in PHP
- How to create a new line in PHP
- How to find string length in PHP
- How to check whether a variable is set or not in PHP
- How to check whether a variable is empty in PHP
- How to check whether a variable is null in PHP
- How to reverse a string in PHP
- How to replace the part of a string with another string in PHP
- Counts how many times a substring occurs in a string in PHP
- How to count all elements or values in an array in PHP
- How to print or echo all the values of an array in PHP
- How to display array structure and values in PHP
- How to reverse the order of an array in PHP
- How to check if a key exists in an array in PHP
- How to remove the last element from an array in PHP
- How to remove the first element from an array in PHP
- How to add elements to the beginning of an array in PHP
- How to add elements to the end of an array in PHP
- How to merge two or more arrays into one array in PHP
- How to sort an array values alphabetically in PHP
- How to remove duplicate values from an array in PHP
- How to randomize the order of an array in PHP
- How to compare two array values in PHP
- How to calculate the sum of values in an array in PHP
- How to remove empty values from an array in PHP
- How to populate dropdown list with array values in PHP
- How to get all the keys of an associative array in PHP
- How to get all the values from an associative array in PHP
- How to sort an associative array by key in PHP
- How to sort an associative array by value in PHP
- How to get single value from an array in PHP
- Foreach loop through multidimensional array in PHP
- How to Delete an Element from an Array in PHP
- How to Check If a String Contains a Specific Word in PHP
- How to Get the Current Date and Time in PHP
- How to Make a Redirect in PHP
- How to Strip All Spaces Out of a String in PHP
- How to Get the Current Year using PHP
- How to Convert a Date from yyyy-mm-dd to dd-mm-yyyy Format in PHP
- How to Convert a String to a Number in PHP
- How to Get the First Element of an Array in PHP
- How to Convert a Date to Timestamp in PHP
- How to Add Elements to an Empty Array in PHP
- How to Convert an Integer to a String in PHP
- How to Delete PHP Array Element by Value Not Key
- How to Push Both Key and Value Into an Array in PHP
- How to Refresh a Page Periodically Using PHP
- How to Remove the Last Character from a String in PHP
- How to Return JSON from a PHP Script
- How to get PHP Errors to Display
Php programming
Use the PHP
isset()functionYou can use the PHP
isset()function to test whether a variable is set or not. Theisset()will returnFALSEif testing a variable that has been set toNULL.Let's check out an example to understand how this function basically works:
need an explanation for this answer? contact us directly to get an explanation for this answer