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Decision making

Logical operators

Conditional operators

Decision Making in C language

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if statement

Selection statement which performs an

indicated action only when the condition is

true

Syntax

if ()

{

.

}

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Example

main( )

{ int age;

scanf(%d,&age);

if (age>=18)

{

printf(\n You can cast your vote !!);

}

}

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if else statement

Selection statement that allows the programmer

to specify different actions to be performed when

condition is true than when the condition is false.

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Example

main( ){ int age;scanf(%d,&age);if (age>=18)

{printf(\n You can cast your vote !!);

}else

{printf(\n You cannot cast your vote !!);

}}

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Nested if . else statement

Test for multiple cases by placing if else inside

other if else

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Example

main( ){ int grade;

scanf(%d,&grade);

if (grade>=90){

if(grade>=95)

printf(\n A+);else

printf(\n A);

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If-else-if ladder

In certain cases multiple conditions are to betested.

In such cases these conditions and their associated

statements can take following form:

if(condition 1)

statement 1;

else if(condition 2)

statement 2;else if(condition 3)

statement 3;

else

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Example

main( ){ int grade;

scanf(%d,&grade);

if (grade>=90) printf(\n A);

else if (grade>=80) printf(\n B);

else if (grade>=70) printf(\n C);

else if (grade>=60) printf(\n D);

else printf(\n F);}

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Exercises

Obtain two numbers from the keyboard and

determine and display which is larger

Obtain a number and print whether the

number is even or odd Obtain three numbers from the keyboard and

determine and display which is larger

Obtain two numbers from user and determine

and print if the first is multiple of the second

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Logical Operators

&& (AND)

|| (OR)

! (NOT)

Bitwise operators

& (Bitwise AND)

| (Bitwise OR)

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Conditional Operators

Expression 1?expression 2:expression 3

If expression 1 is true then the value returned

will be expression 2 otherwise expression 3

Ex. Y=(x>5?3:4)

if(x>5)

Y=3;

else

Y=4;

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Example: Conditional Operators

main( ){

int age;

scanf(%d,&age);

printf( You are );

printf(age

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The switch construct

Instead of using if-else-if ladderthe switchconstruct can be used to handle multiple choices

such as MENU choice.

sw itch(contro l var iable)

case constant-1:

statements(s);

break;

case constant-2:statements(s);

break;

default :

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Example

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