Slide môn học PHP session 2c conditional statements in PHP

the statements in a program execute from the first to the last statement order of flow in a program set of statements only when a... if statementthe specified condition is true condition

Conditional Statements in PHP

Session 7

 Operators are pre-defined symbols that enable us perform specific actions

 Operators enable us to control the

program flow

 The types of operators are:

 Arithmetic operators

 Logical Operators

 Relational Operators

 Bitwise Operators

 Assignment Operators

Review - I

Review - II

 Arithmetic operators are used to perform mathematical operations

 Relational operators compare two operands and determine the relationship between

operands

 Logical operators handle multiple

conditions and combines two or more test expression in a condition

 Bitwise operators operate on the bits of

Objectives

the statements in a program execute

from the first to the last statement

order of flow in a program

set of statements only when a

if statement

the specified condition is true

condition is false

if(condition)

// Code executes if the condition is true

if statement - Example

$a=50;

$b=100;

if($a < $b)

echo "a is less than b";

$a < $b

PHP displays, a is less than b

if …else statement

specified condition is false

if(condition)

{

//Code executes if the condition is true }

else

{

//Code executes if the condition is false

if …else statement - Example

if($a < $b)

{

echo “A is less than B”;

}

else($a > $b)

{

echo “B is less than A”;

}

Nested if statement

else statement

if(condition)

{

//code to be executed }

else

{

//code to be executed if(condition)

{

//code to be executed

Nested if statement - Example

if($a < 500)

{

echo “A is les than 500”;

}

else

{

if ($a >= 500 and $a <= 700)

{

echo “A is between 500 and 700”;

else

{

switch statement - I

multiple values

the value it matches

value of the case statement

matches the value of the switch

variable

Syntax of switch statement

switch(variable)

{

case value1:

//Code executes if condition equals value1

break;

case value2:

//Code executes if condition equals value2

break;

default:

Moves the control to the statements

Example for a switch Statement

switch($var)

{

case Minor:

echo “Not eligible to vote”;

break;

case Major:

echo “Eligible to vote”;

break;

default:

echo “Enter correct value”;

break;

};

Ternary Operator

one line statements

Term1 ? Term2 : Term3;

Term1 - Condition is evaluated

Term2 - Executed if condition is True

Example of Ternary Statement

$x = 100;

$y = 50;

$disp =

($x > $y) ? “X is greater than Y” : “Y is greater than X”;

Condition checked

Summary - I

 Conditional statements execute a set of

statements only when a specified

condition is satisfied

 if statement executes a block of code

only when the specified condition is true

 In a Nested if statement, we specify if

statement within if statement or else

statement

 switch statement checks single variable

against multiple values

switch statement executes a block of code

Summary - II

the statements following the switch statement

of the case statements matches the

value of the switch variable

conditions into one line statements