Branching Statements in C

What is branching in c?

Branching gets its name from the fact that the computer can select which branch to follow.Programs written in the C language execute statements one after the other. Instructions usually need to be altered in order.

A series of instructions can be rearranged in the C programming language using statements. These sentences are referred to as control statements. Moving swiftly between different program portions is made easier by these statements. Control might be transferred unconditionally or under specific restrictions.

Types of branching statements

Here, in branching, we have two categories of branching statements.

1. Conditional branching
2. Unconditional branching

1. Conditional branching

Generally, these are also called selection or decision control statements

It contains the statements that validate the validity of an expression before running the code.A statement from a collection of statements may be processed only by the decision and case-control statements. These also go by the name of conditional statements.

The various types of conditional statements are

• if
• if else
• nested if
• switch
• else if ladder

2. Unconditional branching

Generally, these are also called repetition or loop control statements

No condition is checked by these statements before the code is run. The majority of the time, these statements help moveprogram control from one block to another, and also a series of statements are repeatedly executed until a condition is met by the loop control statement.

The various types of unconditional statements are

• goto
• return
• continue
• break

conditional branching explanation

• if statement

The if statement is a dynamic decision-making construct that can deal with a single condition or a collection of statements. These either take true or false actions. A straightforward if statement with a single block is used when a statement just has one condition.

Syntax

The syntax for the if statement is given as below:

if (condition)
  {
    Block of statements;
  }

Example

//Example program using the if statement

#include <stdio.h>
 int main ()
 {
   int x = 40;
if( x> 20 ) 
   {
printf("x is greater than 20\n" );
   }
printf("value of x is : %d\n", x);
return 0;
}

Output:

x is greater than 20
value of x is: 40

• if else statement

A single condition with two distinct blocks also appears in this sentence. There are two types of blocks: true and false.

Syntax

The syntax for the if-else statement is given as below:

if (condition)
  {
    Block of statements;
  }
else
{
  Block of statements;
}

Example

// Example program using the if else statement

#include <stdio.h>
int main ()
{
int x = 7; 
if( x> 10) 
{
printf("x is greater than 5" ); 
}
else
{
printf(\n"x is less than 5" );
}
printf("The value of x is: %d", x);
return 0;
}

Output

x is less than 5
The value of x is: 7

• nested if statement

Nested if statements refer to if statements that are contained within other if statements.

Syntax

The syntax for the nested if statement is given as below:

if (condition)
  {
if (expression)
  {
    Block of statements;
  }
else
{
    Block of statements;
 }
}
else
{
  Block of statements;
}

Example

// Example program using the nested if statement

#include <stdio.h>
int main( )
{
int a, b, c;
printf("Please enter three numbers: ");
scanf("%d %d %d",&a, &b, &c);
if(a > b)
{
if(a > c)
 {
printf("a is the greatest among the three");
  }
else
{ 
printf("c is the greatest among the three");}
}
else
{
if(b > c)
{
printf("b is the greatest among the three");


}
else
{
printf("c is the greatest among the three");
 }
}
}

Output

Please enter three numbers: 
1
2
4
c is the greatest among the three

• switch statement

The necessity for this kind of statement with numerous alternatives or distinct situations to solve the problem simply and straightforwardly arises when there are multiple conditions present in a problem and it is quite tough to handle such a complex problem with the aid of a ladder if statement. Switch statements are used for this.

Syntax

The syntax for the switch statement is given as below:

switch(expression )
     {
        case constant-expression1:	statements1;
        [case constant-expression2:	statements2;]    
        [case constant-expression3:	statements3;]
        [default : statements4;]
     }

Example

// Example program using the switch statement

#include <stdio.h>
 int main()
{
    int x = 3;
    switch (x) {
    case 1:
printf("answer is 1");
        break;
    case 2:
printf("answer is 2");
        break;
    case 3:
printf("answer is 3");
        break;
    default:
printf("answer other than 1, 2 and 3");
        break;
    }
    return 0;
}

Output

answer is 3

• else-if ladder statement

When multiple criteria are present in a complex problem in sequential order, we can solve the issue simply by using a ladder-if or else-if statement.

Syntax

The syntax for the else if ladder statement is given as below:

if (condition1)
  {
    Block of statements;
  }
else if (condition2)
{
  Block of statements;
}
else if (condition3)
{
  Block of statements;
}
else
{
default statement
}

Example

 // Example program using the else ifladder statement

#include <stdio.h>
void main( )
{
int x;
printf("Please enter a number: ");
scanf("%d", &x);
if(x%2 == 0 && x%3 == 0)
{
printf("The entered number is divisible by both 2 and 3");
}
else if(x%2 == 0)
{
printf("The entered number is divisible by 2");
}
else if(x%3 == 0)
{
printf("The entered number is divisible by 3");
}
else
{
printf("The entered number is divisible by neither 2 nor 3");
}
}

Output

Please enter a number: 6
The entered number is divisible by both 2 and 3

unconditional branching explanation       

• goto

In C programming, a "goto" statement offers an unconditional leap to a designated statement within the same function.

The usage of goto statements is strongly discouraged in all programming languages because they make it difficult to trace a program's control flow, making it difficult to comprehend and alter. Any program that makes use of a goto can be rewritten to do without it.

Syntax

The syntax for the goto statement is given as below:

goto label;
..
.
label: statement;

Example :

// Example program using the gotostatement

#include <stdio.h>
int main () 
{
   int a = 12;
   LOOP:do 
   {
if( a == 12) 
   {
         a = a + 1;
goto LOOP;
      }
printf(" The value of a: %d\n", a);
      a++;
     }
while( a< 20 );
   return 0;
}

Output

The value of a: 13
 The value of a: 14
 The value of a: 15
 The value of a: 16
 The value of a: 17
 The value of a: 18
 The value of a: 19

• Return statement

Returning control to the caller function puts an end to the execution of a function. At the instant after the call, execution picks back up in the caller function. The calling function may also get a value from a return statement. Your function will terminate and return a value to its caller when you use a return statement. In general, the purpose of a function is to take input and provide a result. When a function is prepared to return a value to its caller, the return statement is used.

Syntax

The syntax for the return statement is given as below:

return;
return expression;

Example

// finding the factorial of a number using the return statement

#include<stdio.h>
int factorial(int x); 
int main()
{
    int n;
printf("factorial of the given number : \n\n");
printf("Enter number : ");
scanf("%d", &n);


if(n < 0)
    {
printf("\nFactorial is only defined for positive numbers");
    }


    else
    {
printf("\n%d! = %d", n, factorial(n)); 
    }
    return 0;
}
int factorial(int n)
{
if(n == 0)
    {
        return 1;
    }


    int fact = 1, i;


for(i = n; i> 0; i-- )
    {
        fact = fact * i;
    }
    return fact

Output :

factorial of the given number :
Enter number: 10
10! = 3628800

• Continue statement

In C programming, the continue statement functions similarly to the break statement. It skips any code in between and compels the next iteration of the loop rather than imposing termination.The conditional test and increment sections of the for loop are executed as a result of the continue statement. The continue statement causes the program control to pass the conditional tests for the while and do...while loops.

Syntax:

The syntax for the continue statement is given as below:

Continue;

Example

// Example program using the continue statement

#include <stdio.h>
int main () 
{
   int a = 12;
   LOOP: do 
   {
if( a == 12) 
   {
         a = a + 1;
         continue;
      }
printf(" The value of a: %d\n", a);
      a++;
     }
while( a< 20 );
   return 0;
}

 Output

The value of a: 13
 The value of a: 14
 The value of a: 15
 The value of a: 16
 The value of a: 17
 The value of a: 18
 The value of a: 19

Break statement

There are two uses for the break statement in C programming:

1. When a loop encounters a break statement, the loop is instantly broken, and program control moves on to the statement that follows the loop.

2. It can be applied to the switch statement to end a case.

Syntax

The syntax for the break statement is given as below:

break;

Example

// Example program using the break statement

#include <stdio.h>
int main () 
{
 int a = 10;
while( a< 40 ) 
  {
printf("The value of a: %d\n", a);
      a++;	
if( a> 15) 
      {
         break;
      }
   }
   return 0;
}

Output

The value of a: 10
The value of a: 11
The value of a: 12
The value of a: 13
The value of a: 14
The value of a: 15