Bank interest - C programming example

This program will provide us our bank statement where we will see our total amounts after every year.

Bank interest

C Programming Code

#include<stdio.h>
#include<conio.h>
#include<math.h>
main()
{
    int n;
    float p,r,i,a,b;
    printf(" Enter the amount of money(in BDT): \n ");
    scanf(" %f",&p);
    printf(" Enter the rate of interest between 1-15: \n ");
    scanf(" %f",&r);
    if(r>=1 && r<=15){
        printf(" Enter the time(in year): \n ");
        scanf(" %d",&n);
        i=p*r*n;
        a=i/100;
        b=p+a;
        printf(" The principal with interest is %.2f. \n ",b);
    }
    else{
        printf(" Please enter a valid rate of interest.\n ");
    }
    getch();
}

Output of the code

Bank Interest

Explanation of the code

#include<stdio.h>

#include<conio.h>

Ø This are called header file. A header file is a file with extension .h which contains C function declarations and macro definitions to be shared between several source files The C programming language provides many standard library functions for file input and output. These functions make up the bulk of the C standard library header <stdio.h>.In the other hand <conio.h> is a C header file used mostly by MS-DOS compilers to provide console input/output. It is not part of the C standard library or ISO C. This header declares several useful library functions for performing "console input and output" from a program.

· main()

Ø In C, program execution starts from the main() function. The main function can in-turn call other functions. When main calls a function, it passes the execution control to that function. The function returns control to main when a return statement is executed or when end of function is reached.

· int n

Ø int is a variable or data type. A variable declared to be of type int can be used for storing integer numbers (values which doesn’t contain decimal places). Here we declare “n” as int type. So this variables can take only integer values.

· float p, r, i, a, b;

Ø float is a variable or data type. A variable declared to be of type float can be used for storing floating-point numbers (values containing decimal places). Here we declare “p” , “r” , “i” , “a” , and “b” variable in float type. So this three variable can take values containing decimal number.

· printf() function

Ø C uses printf() function to write from the input devices. This function has been declared in the header file called stdio.h . Any text written within the pair of quotes ("") is displayed as such by printf() function on the screen.

· scanf() function

Ø This function is used to get input from the user of the program. Here is 3 scanf functions, scanf(“%f”,&p) is used here. So, this program will read in a float value for “p” variable that the user enters on the keyboard (%f is for float values. As there is “&p”, the number user enters will be the value of “p” variable). scanf(“%f”,&r”) is used here. So, this program will read in a float value for “n” variable that the user enters on the keyboard (%f is for float values. As there is “&r”, the number user enters will be the value of “r” variable).scanf(“%d”,&n”) is used here. So, this program will read in a integer value for “n” variable that the user enters on the keyboard (%d is for integer values. As there is “&n”, the number user enters will be the value of “n” variable).

· if else loop

Ø If the expression evaluates to true, then the if block will be executed, otherwise, the else block will be executed. Here, we can see that in the brackets of if loop, there is a expression “r>=1 && r<=15” .If the entered value of r is greater than or equals to 1 and less than or equals to 15, the code within if block will be executed. If not so, then the code within else block will be executed.

· getch() function

getch() is used to hold the console(output) window on the screen after the whole program run is completed till the user enters a key from keyboard. This function is present in the header file called conio.h.

Now lets see this code in a flowchart