The document outlines different control structure statements in C programming including simple if, if-else, else-if ladder, nested if-else, switch, and goto statements. It provides examples of the syntax for each statement type and discusses how they can be used to make decisions in code based on different conditions. The lecture also briefly explains each statement and when they would be applicable to solve different programming problems.

1. Lecture04(Control Structure PART-I)
June 22, 2010
Today's Outline
Decision making statements in C
• Simple if statement
• if_else statement
• else_if ladder
• nested if_else statement
• switch statement
• goto statement
Md. Mahbub Alam Structured Programming Language 1
(CSE-1121)

2. Simple if Statement
Format:
If ( test condition )
statements;
scanf( “ %f “ , &marks );
if( marks >= 80 )
printf( "Yes, the student get A+“ );
Md. Mahbub Alam Structured Programming Language 2
(CSE-1121)

3. if_else Statement
Format:
if ( test condition )
statements;
else
statements;
if( num % 2 == 0 )
printf( “Even number“ );
else
printf( “Odd number” );
Md. Mahbub Alam Structured Programming Language 3
(CSE-1121)

4. else_if ladder Statement
Format:
if(condition 1) if( marks > 79 )
statements; printf( " Honours “ );
else if(condition 2) else if( marks > 59 )
statements; printf( " First Division “ );
else if(condition) else if( marks > 49 )
statements; printf( " Second Division “ );
.............. .. else if( marks > 39 )
.............. .. printf( " Third Division “ );
else if(condition n) else
statements; printf(" Fail ");
else
default statement;
Md. Mahbub Alam Structured Programming Language 4
(CSE-1121)

5. nested if_else Statement
Format:
if ( condition ) if(a>b)
if ( condition ) {
if(a>c)
statement1; printf("a is the largest:%d",a);
else else
statement2; printf("c is the largest:%d",c) ;
else }
statement3 else
{
if(c>b)
printf("c is the largest:%d",c);
else
printf("b is the largest:%d",b) ;
}
Md. Mahbub Alam Structured Programming Language 5
(CSE-1121)

6. switch Statement
index=marks/10;
Format: switch (index)
{
Switch ( expression ) case 10:
case 9:
{
case 8:
case constant1: printf(" Honours ");
statements; break;
break; case 7:
case 6:
case constant2:
printf(“ First Division ");
statements; break;
break; case 5:
............... printf(“ Second Division ");
break;
...............
case 4:
default: printf(“ Third Division ");
statements; break;
break; default:
} printf( “ Fail ");
break;
}
Md. Mahbub Alam Structured Programming Language 6
(CSE-1121)

7. goto Statement
Format:
goto label; main()
......... {
......... double x,y;
label: read:
statements; scanf("%lf",&x);
if(x<0)
label:
goto read;
statements;
y=sqrt(x);
.........
printf("%lf",y);
.........
}
goto label;
Md. Mahbub Alam Structured Programming Language 7
(CSE-1121)

8. Any Question?
Md. Mahbub Alam Structured Programming Language 8
(CSE-1121)

9. Thank You All
Md. Mahbub Alam Structured Programming Language 9
(CSE-1121)