Blog For C Programming: control statement

Showing posts with label control statement. Show all posts

Wednesday, February 4, 2015

C continue statement

The continue statement in C language is used to continue the execution of loop (while, do while and for). It is used with if condition within the loop.

In case of inner loops, it continues the control of inner loop only.

Syntax:

jump-statement;
continue;

The jump statement can be while, do while and for loop.

Example of continue statement in c

#include <stdio.h>
#include <conio.h>
void main(){
int i=1;//initializing a local variable
clrscr();
//starting a loop from 1 to 10
for(i=1;i<=10;i++){
if(i==5){//if value of i is equal to 5, it will continue the loop
continue;
}
printf("%d \n",i);
}//end of for loop
getch();
}

Output

As you can see, 5 is not printed on the console because loop is continued at i==5.

C continue statement with inner loop

In such case, C continue statement continues only inner loop, but not outer loop.

#include <stdio.h>
#include <conio.h>
void main(){
int i=1,j=1;//initializing a local variable
clrscr();
for(i=1;i<=3;i++){
for(j=1;j<=3;j++){
if(i==2 && j==2){
continue;//will continue loop of j only
}
printf("%d &d\n",i,j);
}
}//end of for loop
getch();
}

Output

As you can see, 2 2 is not printed on the console because inner loop is continued at i==2 and j==2.

C break statement

The break statement in C language is used to break the execution of loop (while, do while and for) and switch case.

In case of inner loops, it terminates the control of inner loop only.

There can be two usage of C break keyword:

With switch case
With loop

Syntax:

jump-statement;
break;

The jump statement in c break syntax can be while loop, do while loop, for loop or switch case.

Flowchart of break in c

Example of C break statement with switch case

Click here to see the example of C break with switch statement.

Example of C break statement with loop

#include <stdio.h>
#include <conio.h>
void main(){
int i=1;//initializing a local variable
clrscr();
//starting a loop from 1 to 10
for(i=1;i<=10;i++){
printf("%d \n",i);
if(i==5){//if value of i is equal to 5, it will break the loop
break;
}
}//end of for loop
getch();
}

Output

As you can see on console output, loop from 1 to 10 is not printed after i==5.

C break statement with inner loop

In such case, it breaks only inner loop, but not outer loop.

#include <stdio.h>
#include <conio.h>
void main(){
int i=1,j=1;//initializing a local variable
clrscr();
for(i=1;i<=3;i++){
for(j=1;j<=3;j++){
printf("%d &d\n",i,j);
if(i==2 && j==2){
break;//will break loop of j only
}
}
}//end of for loop
getch();
}

Output

As you can see the output on console, 2 3 is not printed because there is break statement after printing i==2 and j==2. But 3 1, 3 2 and 3 3 is printed because break statement works for inner loop only.

Tuesday, February 3, 2015

C Switch Statement

The switch statement in C language is used to execute the code from multiple conditions. It is like if else-if ladder statement.

The syntax of switch statement in c language is given below:

switch(expression){

case value1:

//code to be executed;

break; //optional

case value2:

//code to be executed;

break; //optional

......

default:

code to be executed if all cases are not matched;

}

Rules for switch statement in C language

1) The switch expression must be of integer or character type.

2) The case value must be integer or character constant.

3) The case value can be used only inside the switch statement.

4) The break statement in switch case is not must. It is optional. If there is no break statement found in switch case, all the cases will be executed after matching the case value. It is known as fall through state of C switch statement.

Let's try to understand it by the examples. We are assuming there are following variables.

int x,y,z;
char a,b;
float f;

Valid Switch	Invalid Switch	Valid Case	Invalid Case
switch(x)	switch(f)	case 3;	case 2.5;
switch(x>y)	switch(x+2.5)	case 'a';	case x;
switch(a+b-2)		case 1+2;	case x+2;
switch(func(x,y))		case 'x'>'y';	case 1,2,3;

Flowchart of switch statement in C

Let's see a simple example of c language switch statement.

#include<stdio.h>

#include<conio.h>

void main(){

int number=0;

clrscr();

printf("enter a number:");

scanf("%d",&number);

switch(number){

case 10:

printf("number is equals to 10");

break;

case 50:

printf("number is equal to 50");

break;

case 100:

printf("number is equal to 100");

break;

default:

printf("number is not equal to 10, 50 or 100");

}

getch();

}

Output


enter a number:4

number is not equal to 10, 50 or 100


enter a number:50

number is equal to 50

C Switch statement is fall-through

In C language, switch statement is fall through, it means if you don't use break statement in switch case, all the case after matching case will be executed.

Let's try to understand the fall through state of switch statement by the example given below.

#include<stdio.h>

#include<conio.h>

void main(){

int number=0;

clrscr();

printf("enter a number:");

scanf("%d",&number);

switch(number){

case 10:

printf("number is equals to 10\n");

case 50:

printf("number is equal to 50\n");

case 100:

printf("number is equal to 100\n");

default:

printf("number is not equal to 10, 50 or 100");

}

getch();

}

Output


enter a number:10

number is equals to 10

number is equals to 50

number is equals to 100

number is not equal to 10, 50 or 100


enter a number:50

number is equal to 50

number is equals to 100

number is not equal to 10, 50 or 100

C if else Statement

The if statement in C language is used to perform operation on the basis of condition. By using if-else statement, you can perform operation either condition is true or false.

There are many ways to use if statement in C language:

If statement
If-else statement
If else-if ladder
Nested if

If Statement

The single if statement in C language is used to execute the code if condition is true. The syntax of if statement is given below:

if(expression){

//code to be executed

}

Flowchart of if statement in C

Let's see a simple example of c language if statement.

#include<stdio.h>

#include<conio.h>

void main(){

int number=0;

clrscr();

printf("enter a number:");

scanf("%d",&number);

if(number%2==0){

printf("%d is even number",number);

}

getch();

}

Output


enter a number:4

4 is even number


If-else Statement

The if-else statement in C language is used to execute the code if condition is true or false. The syntax of if-else statement is given below:



if(expression){  

//code to be executed if condition is true  

}else{  

//code to be executed if condition is false  

}


Flowchart of if-else statement in C



Let's see the simple example of even and odd number using if-else statement in C language.\



#include<stdio.h>  

#include<conio.h>  

void main(){  

int number=0;  

clrscr();  

  

printf("enter a number:");  

scanf("%d",&number);  

  

if(number%2==0){  

printf("%d is even number",number);  

}  

else{  

printf("%d is odd number",number);  

}  

getch();  

}


Output


enter a number:4

4 is even number



enter a number:5

5 is odd number



If else-if ladder Statement

The if else-if statement is used to execute one code from multiple conditions. The syntax of if else-if statement is given below:



if(condition1){  

//code to be executed if condition1 is true  

}else if(condition2){  

//code to be executed if condition2 is true  

}  

else if(condition3){  

//code to be executed if condition3 is true  

}  

...  

else{  

//code to be executed if all the conditions are false  

} 




Flowchart of else-if ladder statement in C



The example of if-else-if statement in C language is given below.



#include<stdio.h>  

#include<conio.h>  

void main(){  

int number=0;  

clrscr();  

  

printf("enter a number:");  

scanf("%d",&number);  

  

if(number==10){  

printf("number is equals to 10");  

}  

else if(number==50){  

printf("number is equal to 50");  

}  

else if(number==100){  

printf("number is equal to 100");  

}  

else{  

printf("number is not equal to 10, 50 or 100");  

}  

getch();  

}




Output


enter a number:4

number is not equal to 10, 50 or 100



enter a number:50

number is equal to 50

Pages

Wednesday, February 4, 2015

C continue statement

C continue statement

Syntax:

Example of continue statement in c

Output

C continue statement with inner loop

Output

C break statement

C break statement

Syntax:

Flowchart of break in c

Example of C break statement with switch case

Example of C break statement with loop

Output

C break statement with inner loop

Output

Tuesday, February 3, 2015

C Switch Statement

C Switch Statement

Rules for switch statement in C language

Flowchart of switch statement in C

Output

C Switch statement is fall-through

Output

C if else Statement

C if else Statement

If Statement

Flowchart of if statement in C

Output

If-else Statement

Flowchart of if-else statement in C

Output

If else-if ladder Statement

Flowchart of else-if ladder statement in C

Output