C if statement
What is C if statement
To conditionally execute statements,
you can use the if or the if...else statement.
Syntax for if statement
The general form of the if statement is
if(expr) {// w w w.j av a 2s . c o m
s1 ;
s2 ;
....
}
expr is a Boolean expression that
returns true (nonzero) or false (zero).
Example for if statement
if statement with a comparison operator. The code compares two int values.
#include <stdio.h>
//from ww w . j av a2 s .c o m
main(){
int i = 3,j = 5;
if(i < j){
printf("i < j \n");
}
}
The code above generates the following result.
If a compound statement is used, it must be enclosed in opening and closing braces.
#include<stdio.h>
/*from w ww .j a va2s .co m*/
main()
{
int i=5, j =1;
if (i > j){
i = i + 1;
printf("%d",i);
}
else
j = j +1;
}
The code above generates the following result.
Syntax for nested if Statements
if(expression1){
StatementA; //from w w w .j a v a 2 s . co m
if(expression2){
StatementB;
}else {
StatementC;
}
}
else {
StatementD;
}
Statement E;
Example for nested if Statements
Use nested if statement to check long value.
#include <stdio.h>
#include <limits.h>
//from w ww. java 2 s . c o m
int main(void)
{
long test = 0L;
if( test % 2L == 0L) {
printf("The number %ld is even", test);
if ( (test/2L) % 2L == 0L)
{
printf("\nHalf of %ld is also even", test);
printf("\nThat's interesting isn't it?\n");
}
}
else
printf("The number %ld is odd\n", test);
return 0;
}
The code above generates the following result.
