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The ones who are crazy enough to think they can change the world are the ones who do.
- Steve Jobs

C if statement

Why if Statement?

All programming languages enable you to make decisions. They enable the program to follow a certain course of action depending on whether a particular condition is met. This is what gives programming language their intelligence.

if statement in C

C if Syntax And Definition

  • C uses the keyword if to execute a set of statements when logical condition is true.
  • When the logical condition is false, the compiler simply skips the statement within the block.
  • The "if" statement is also known as one way decision statement.

Syntax if statement

Syntax
if(condition)
{
here goes statements;
.
.
.
.
here goes statements;
}

if Statement Uses

if statements are commonly used in following scenarios

  • Is A bigger than B?
  • Is X equal to Y?
  • Is M not equal to N?

Realtime Time if Statement Uses

if statement in real time

Arduino microcontroller make use C programming, where you need to blink a warning light(red light) when certain condition met. Example program is as below:

realtimeif
if(x = 123)
digitalWrite(LEDpin, high)

Note:

x is a variable which get its input from a sensor continuously.

if Statement Rules

  • The expression (or) condition is always enclosed within pair of parenthesis. e.g.) if ( a > b )
  • The if statement should not be terminated with a semicolon. If it happens, the block of statements will not execute even the condition is true.
  • The statements following the if condition is normally enclosed between 2 braces (in curly braces).

if statement Flow Chart

Following flow chart will clearly explain how if statement works

if statement flow chart

if statement C Program

ifstatement.c
#include <stdio.h> //header file section
#include <conio.h>
int main()
{
int age = 18;
if(age > 17){
printf("you are eligible for voting ");
}
printf("\nThis is normal flow ");
return 0;
}
  • you are eligible for voting
  • This is normal flow

Note:

If the user input is greater than 17, then the condition will be true and the statements under if condition gets executed. Otherwise, it executes next to the if block.

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