if else statements are very basic blocks to check condition(boolean expression) to execute appropriate block.
SYNTAX:
<?php
if (booleanExpression) {
// if booleanExpression is True this code will execute
your code here….
} else {
// if booleanExpression is False this code will execute
your code here….
}
?>
Example 1 :
In below example, if block will be executed if x is greater than 11. Otherwise, the else block will be executed.
<?php
$x = 10;
if ($x > 6) {
print "x > 6 is true, if block execute. "
}
else{
print "x > 6 is false then else block execute. "
}
?>
------------ ****** ------------
OUTPUT:
x > 6 is true, if block execute.
Example 2 :
In below example, if block will be executed if x is greater than 11. Otherwise, the else block will be executed.
<?php
$x = 9;
if ($x > 11){
print "x > 11 is true, if block will execute. ";
}
else{
print "x > 11 is false then else block will execute. ";
}
?>
------------ ****** ------------
OUTPUT:
x > 11 is false so else block will execute.
Example 3 :
If there is only one line code inside an if or else block, the curly braces ({) are optional.
<?php
$x = 9;
if ($x > 11)
print "x > 11 is true, if block will execute. "
else
print "x > 11 is false then else block will execute. "
?>
------------ ****** ------------
OUTPUT:
x > 11 is false so else block will execute.
if there are many condition need to check then we can use ifelse block.
SYNTAX:
<?php
if (booleanExp_1) {
// booleanExp_1 is True then this block code will execute.
} else if (booleanExp_2) {
// booleanExp_2 is True then this block code will execute.
}
else {
// if all upper conditions will fail(False) then this block code will execute.
}
?>
Example 4:
If there are many conditions in else-if then which condition is true that block code will execute. .
<?php
$c = 3;
if ($c == 1) { // False
print "one"
}else if ($c == 2) { // False
print "two"
}else if ($c == 3) { // True
print "three"
} else {
print "invalid"
}
?>
------------ ****** ------------
OUTPUT:
three
Example 5:
If there are many conditions then, if all conditions are false then always else block code will execute.
<?php
$c = 5;
if ($c == 1) { // False
print "one"
} else if ($c == 2) { // False
print "two"
} else if ($c == 3) { // False
print "three"
} else {
print "All expressions are false, else block executed."
}
?>
------------ ****** ------------
OUTPUT:
All expressions are false, else block executed.
See how to use && and || operators for if else expressions.
For && both conditions should be True then it will True.
For || any one conditions is True then it will True.
Example 6 :
Taking example for use of && operator.
<?php
$c = 5;
if ($c == 1 && $c == 5) { // False
print "if block (c == 1 && c == 5) is executed"
} else if ($c == 5 && $c < 10) { // True
print "elseif block (c == 5 && c < 10) is executed"
} else {
// This upper both expressions are False then this block code execute.
print "else block is executed"
}
?>
------------ ****** ------------
OUTPUT:
elseif block (c == 5 && c < 10) is executed
Example 7:
Taking example for use of || operator.
<?php
$c = 5;
if ($c == 1 || $c == 5) { // True
print "if block (c == 1 || c == 5) is executed"
} else if ($c == 6 || $c < 10) { // False
print "elseif block (c == 6 || c < 10) is executed"
} else {
// This upper both expressions are False then this block code execute.
print "else block is executed"
}
?>
------------ ****** ------------
OUTPUT:
if block (c == 1 || c == 5) is executed
Internallly Switch statement working is same as elseif blocks.
switch accept condition and contain many case statements, Whenever case statement is true then that
case block code will execute, when found break then case statement will break and execution will out from switch statement.
SYNTAX:
<?php
switch (condition) {
case value_1 :
// You Code Here….
break;
case value_2 :
// You Code Here….
break;
.
.
.
.
case value_n :
// You Code Here….
break;
default:
// You Code Here….
}
?>
Example 8:
In below example, if block will be executed if x is greater than 11.
Otherwise, the else block will be executed.
<?php
$a = 1;
switch ($a) {
case 1 :
print "First case.";
break;
case 2 :
print "Second case.";
break;
case 3 :
print "Third case.";
break;
default: // if none of the case
print "Default."
} // Switch close
?>
------------ ****** ------------
OUTPUT:
First case.
Example 9:
if we will not take break in case statement, then switch will executed for other case until found break or default statement.
<?php
$a = 2;
switch ($a) {
case 1 :
print "First case.";
break;
case 2 :
print "Second case.";
case 3 :
print "Third case.";
default: // if none of the case
print "Default.";
} // Switch close
?>
------------ ****** ------------
OUTPUT:
Second case.
Third case.
Default.
Example 10:
We can use nested Switch statements.
<?php
$a = 1;
$b = 2;
switch ($a) {
case 1 :
print "Outer First case.";
// When case 1 is true then inner switch will call
// Inner switch statement start
switch ($b) {
case 1 :
print "Inner First case.";
break;
case 2 :
print "Inner Second case.";
break;
default: // if none of the case
print "Inner Default.";
} // Switch close
// Inner switch statement end
break;
case 2 :
print "Outer Second case.";
break;
default: // if none of the case
print "Outer Default.";
} // Switch close
?>
------------ ****** ------------
OUTPUT:
Outer First case.
Inner Second case.