PHP If Else Statement

In this tutorial, you shall learn about If-Else conditional statement in PHP, its syntax, and how to use an if-else statement in programs with the help of some examples.

PHP If Else

PHP If Else statement is a conditional statement that can execute one of the two blocks of statements based on the result of an expression.

Syntax

The syntax of PHP If-Else statement is

if (condition) {
  // if-block statement(s)
} else {
  // else-block statement(s)
}

where

• if is a keyword.
• condition is a boolean expression.
• if-block statement(s) are a block of statements. if-block can contain none, one or more PHP statements.
• else is a keyword.
• else-block statement(s) are a block of statements. else-block can contain none, one or more PHP statements.

If the condition evaluates to true, PHP executes if-block statement(s). If the condition is false, PHP executes else-block statement(s).

Example

The following is a simple PHP program to demonstrate the working of If-Else conditional statement.

We take two variables and assign values to each of them. Then we use if-statement to check if the two variables are equal.

Here, the condition is a equals b ?.

PHP Program

<?php
  $a = 4;
  $b = 4;
  if ($a == $b) {
    echo "a and b are equal.";
  } else {
    echo "a and b are not equal.";
  }
?>

Output

Nested If-Else

if-else itself if a statement just like an echo statement.

Since if-else is a statement, we can write an if-else in the if-block or else-block. If we have an if-else statement inside an if-else statement, it is called nested if-else statement.

In the following PHP program, we write a nested if-else program, to find out the largest of the given three numbers.

PHP Program

<?php
  $a = 4;
  $b = 1;
  $c = 9;
  if ($a > $b && $a > $c) {
    echo "a is the largest.";
  } else {
    if ($b > $c) {
      echo "b is the largest.";
    } else {
      echo "c is the largest.";
    }
  }
?>

Output

Conclusion

In this PHP Tutorial, we learned about if-else statement, and how to use if-else statement in a PHP program, with the help of examples.