operators and expression :
Operator is a symbol that tells the compiler to perform all mathematical or logical tasks.
Types of operators :
Decision statements :
- If statement
- If….else statement
- Nested if statement
- If-else-if ladder
- Switch statement
- Jump statement
Importent Keywords:
1)break
2)continue
3)goto
4)return
1) if statement :
if statement is the most simple decision-making statement. It is used to decide whether a certain statement or block of statements will be executed or not i.e if a certain condition is true then a block of statement is executed otherwise not.
if(condition)
{
// Statements to execute if
// condition is true
}
Write a c program to check whether the entered number is less than 10
#include<stdio.h>
int main() {
int n;
printf("enter the numbers\n");
scanf("%d",&n);
if(n<10){
printf("entered no is less than 10\n");
}
return 0;
} enter the numbers
9
entered no is less than 10
#include<stdio.h> int main() {
int n,m ;
printf("enter the numbers\n");
scanf("%d%d",&n,&m);
if(m==n){
printf("both are equal");
}
return 0;
}
Output :
enter the numbers
5
5
both are equal
Write a c program to check whether the candidate age is greater than 17
or not .if yes,display message “Eligible for voting’’.
#include<stdio.h> int main() {
int age ;
printf("enter the age\n");
scanf("%d", &age);
if(age>17){
printf("eligible for voting\n");
}
return 0;
}
Output :
enter the age
32
eligible for voting
2) if– else statement :
The if statement alone tells us that if a condition is true it will execute a block of statements and if the condition is false it won’t. But what if we want to do something else if the condition is false. Here comes the C else statement. We can use the else statement with if statement to execute a block of code when the condition is false.
if (condition) { // Executes this block if // condition is true } else { // Executes this block if // condition is false }
Example
Write a c program both value same or not :
#include<stdio.h>
int main() {
int a,b;
printf("enter the value of a\n");
scanf("%d",&a);
printf("enter the value of b\n");
scanf("%d",&b);
if(a==b){
printf("both are equal\n");
}
else {
printf("both are not equal\n");
}
return 0;
}
Output :
enter the value of a
2
enter the value of b
2
both are equal
#include<stdio.h> int main() {
int a = 20;
if (a < 15){
printf("a is smaller than 15");
}
else{
printf("a is greater than 15");
}
return 0;
}
Output :
a is greater than 15
Write a c program to check whether number is even or odd :
#include<stdio.h>
int main (){
int n;
printf("enter the numbers\n");
scanf("%d",&n);
if(n%2==0)
{
printf("%d is a even no\n",n);
}
else {
printf("%d is not a even no\n",n);
}
return 0;
}
Output :
enter the numbers
5
5 is not a even no
Write a c program to check a person is eligible for voting or not
#include<stdio.h>
int main (){
int age;
printf("enter the age\n");
scanf("%d",&age);
if(age>=80)
{
printf("eligible for voting",age);
}
else {
printf(" not eligible for voting",age);
}
return 0;
}
Output :
enter the age
88
eligible for voting
Write a c program to check vowels or not:
#include<stdio.h>
int main (){
char c ;
printf("enter the alphabet\n");
scanf("%c",&c);
if(c=='A'|| c=='a'||c=='E'||c=='e'||c=='I'|| c=='i'||c=='O'||c=='o'||c=='U'||c=='u')
{
printf("it is a vowels ");
}
else {
printf("it is a consonant ");
}
return 0;
}
Output :
enter the alphabet
a
it is a vowels
Write a c program to calculate the salary of an engineering representative based on the sales . bonus and incentive to be offered to him will be based on total sales.if the sales exceed Rs=10,000/-follow the particulars of table (1) and (2)
Table 1 Table 2
Basic = 3000 Basic = 3000
Hra = 20% of basic Hra = 20% of basic
Da = 110% of basic Da = 110% of basic
Conveyance= Rs = 500 Conveyance= Rs = 500
Incentive = 10% of sales Incentive = 5% of sales
Bonus = RS 500 Bonus = RS 200
#include<stdio.h>
int main (){
float bs,hra,da,cv,incentive,bonus,sale,totalsales;
printf("enter the total sales\n");
scanf("%f",&sale);
if(sale > 1000000){
bs=3000;
hra=20*bs/100;
da=110*bs/100;
cv=500;
incentive=sale*10/100;
bonus = 500;
}
else{
bs=3000;
hra=20*bs/100;
da=110*bs/100;
cv=500;
incentive=sale*5/100;
bonus = 200;
}
total sales = bs+hra+da+cv+incentive+bonus;
printf("\ntotal sales %f",sale);
printf("\n basic salary %f",bs);
printf("\n hra %f",hra);
printf("\n da %f",da);
printf("\n cv %f",cv);
printf("\n inc %f",incentive);
printf("\n bonus %f",bonus);
printf("\n gross salary %f", totalsales);
return 0;
}
Output:
enter the total sales
10,0000
total sales 10.000000
basic salary 3000.000000
hra 600.000000
da 3300.000000
cv 500.000000
inc 0.500000
bonus 200.000000
gross salary 7600.500000
3) Nested if-else statement
It is always legal in C programming to nest if-else statements, which means you can use one if or else if statement inside another if or else if statement(s).
if( boolean_expression 1){
/* Executes when the boolean expression 1 is true */
if(boolean_expression 2) {
/* Executes when the boolean expression 2 is true */
}
}
Example
Write a program to calculate energy bills. Read the starting and ending meter reading the charge are as follows
No of units consumed rates in (rs)
200-500 3.50
100-200 2.50
Less than 100 1.50
#include<stdio.h> int main() {
int initial,final,consumed;
float total;
printf("enter the initial readings\n");
scanf("%d",&initial);
printf("enter the final readings\n");
scanf("%d",&final);
consumed = final - initial;
if(consumed>=200 && consumed<=500)
total = consumed*3.50;
else if(consumed>=100 && consumed<1200 0="" bill="" consumed="" d="" else="" f="" getchar="" if="" is="" of="" printf="" return="" total="" units=""> Output :
enter the initial readings
800
enter the final readings
850
total bill of 50 units is 75.000000
4) if-else if Ladder
All the values of the variable check with different conditions.
Example
Write a program to find the largest number out of three numbers Read the numbers through the keyword.
#include<stdio.h>
int main (){
int a,b,c;
printf("enter the value of a:");
scanf("%d",&a);
printf("enter the value of b:");
scanf("%d",&b);
printf("enter the value of c:");
scanf("%d",&c);
printf("largest out of three numbers: ");
if(a>b){
if(a>c){
printf("a = %d\n ",a);
}
else{
printf("c = %d\n ",c);
}
}
else{
if(c>b){
printf("c = %d\n ",c);
}
else{
printf("b = %d\n ",b);
}
}
}
Output:
enter the value of a:12
enter the value of b:23
enter the value of c:56
largest out of three numbers: c = 56
5) Switch Statement :
A switch statement is a multiway branch statement in the program if there is a possibility to make a choice from a number of options.
Executed default statement .
Syntax:
Switch (variable name)
Case 1:
//Statement;
Break;
Case 2:
//Statement ;
Break;
Default:
//Statement:
#include<stdio.h>
int main(){
int a,b,c;
char op;
printf("\nenter the operator\n");
scanf("%c",&op);
printf("enter the value of a: ");
scanf("%d",&a);
printf("enter the value of b: ");
scanf("%d",&b);
switch(op){
case '+':
c = a+b;
break;
case '-':
c = a-b;
break;
case '*':
c = a*b;
break;
case '/':
c = a/b;
break;
case '%':
c = a%b;
break;
}
printf("calculation is %d ", c);
return 0;
}
Output :
enter the operator
+
enter the value of a: 56
enter the value of b: 78
calculation is 134
Write a program to display the names of the days of week.
#include<stdio.h>
void main (){
int day,i;
printf("enter the no between 1 to 7: ");
scanf("%d",&day);
switch(day){
case 1:
printf("1st day of the week is Sunday");
break;
case 2:
printf("2nd day of the week is Monday");
break;
case 3:
printf("3rd day of the week is Tuesday");
break;
case 4:
printf("4th day of the week is Wenesday");
break;
case 5:
printf("5th day of the week is Thursday");
break;
case 6:
printf("6th day of the week is Friday");
break;
case 7:
printf("7th day of the week is Saturday");
break;
}
}
Output:
enter the no between 1 to 7: 4
4th day of the week is Wednesday