The For Statement in C programming
The For Statement
The for repetition statement handles all the details of counter-controlled repetition. The general format of the for statement:
for ( exp1; exp2; exp3 ) {
statement
}
Often, exp1 and exp3 are comma-separated lists of expressions. The commas as used here are actually comma operators that guarantee that lists of expressions evaluate from left to right.
The value and type of a comma-separated list of expressions are the value and type of the rightmost expression in the list.
The following code demonstrates the for statement:
// Summation with for (odd numbers from 2 to 100)
#include <stdio.h>
// function main begins program execution
int main( void )
{
unsigned int sum = 0; // initialize sum
unsigned int number; // number to be added to sum
for ( number = 2; number <= 100; number += 2 ) {
sum += number; // add number to sum
} // end for
printf( "Sum is %u\n", sum ); // output sum
} // end function main
Output:
Sum is : 2550
Another example using the For Statement
The c program below demonstrates the use of for statement to calculate the compound interest.
// Calculating compound interest
#include <stdio.h>
#include <math.h>
// function main begins program execution
int main( void )
{
double amount; // amount on deposit
double principal = 1000.0; // starting principal
double rate = .05; // annual interest rate
unsigned int year; // year counter
// output table column heads
printf( "%4s%21s\n", "Year", "Amount on deposit" );
// calculate amount on deposit for each of ten years
for ( year = 1; year <= 10; ++year ) {
// calculate new amount for specified year
amount = principal * pow( 1.0 + rate, year );
// output one table row
printf( "%4u%21.2f\n", year, amount );
} // end for
} // end function main
Output:
Year Amount on deposit
1 1050.00
2 1102.50
3 1157.63
4 1215.51
5 1276.28
6 1340.10
7 1407.10
8 1477.46
9 1551.33
10 1628.89
Note: This example made use of the <math.h> library, which we will discuss in C Math tutorial.
Ads Right
