if (expression) { statements or block or statements }The expression is evaluated by the if statement return a boolean value (i.e. either true or false).
If we have two variable $x and $y to be evaluated in if condition then, if($x == $y) : returns true if x is equal to y if($x != $y) : returns true if x is not equal to y if($x < $y) : returns true if x is less than y if($x > $y) : returns true if x is greater than y if($x <= $y) : returns true if x is less than or equal to y if($x >= $y) : returns true if x is greater than or equal to y |
<?php $a = 20; $b = 20; $c = 20; if($a == $b) // a is equal to b , hence returns boolean true { echo "Value of a = ".$a."<br>"; echo "Value of b = ".$b."<br>"; echo "a is equal to b"; } if($a == $c) // a is not equal to b , hence returns boolean false { echo "Value of a = ".$a."<br>"; echo "Value of c = ".$c."<br>"; echo "a is equal to c"; } ?>
In the above example value of a and b is equal hence first if condition returns TRUE, so the if block is being executed. Where as a and c are not equal thus if block two is not executed.Output
Value of a = 20 Value of b = 20 a is equal to b
if (expression) { statement or block or statements } else { statements or block or statements }
<?php $a = 20; $b = 20; $c = 20;
/* a is equal to b, hence returns boolean true and "if" block is executed */
if($a == $b) { echo "Value of a = ".$a."<br>"; echo "Value of b = ".$b."<br>"; echo "a is equal to b<br><br>"; } else { echo "Value of a = ".$a."<br>"; echo "Value of b = ".$b."<br>"; echo "a is not equal to b<br><br>"; }
/* a is not equal to b , hence returns boolean false and "else" block is executed */
if($a == $c) { echo "Value of a = ".$a."<br>"; echo "Value of c = ".$c."<br>"; echo "a is equal to c"; } else { echo "Value of a = ".$a."<br>"; echo "Value of c = ".$c."<br>"; echo "a is not equal to c<br>"; } ?>
The if-else statement just improvises the if statement example. If a statement returns boolean false then now the else block is being executed.Output
Value of a = 20 Value of b = 20 a is equal to b Value of a = 20 Value of c = 20 a is equal to c
If we have only one statement in if or else condition statements, we do not require braces e.g. if(2 > 5) echo "2 > 5 : true"; else echo "2 > 5 : false"; |
<?php $day=5; if($day == 1) echo "Its a Monday!"; elseif ($day == 2) echo "Its a Tuesday!"; elseif ($day == 3) echo "Its a Wednesday!"; elseif ($day == 4) echo "Its a Thursday!"; elseif ($day == 5) echo "Its a Friday!"; elseif ($day == 6) echo "Its a Saturday!"; else { echo "Its a Sunday!!<br>"; echo "Its a Holiday!!<br>"; } ?>
Output
Its a Friday!