/Get Starting With C "Variables and Arithmetic operations"

Get Starting With C "Variables and Arithmetic operations"

In the previous article , we talked about how to type a code in C , compile it and run it . In this one I’ll go through Variables and Arithmetic operations .
First , here’s a table of some variable types in C
 

Type Number of bytes Range
signed char 1 -128 to +127
short int 2 -32,768 to +32,767
int 4 -2,147,438,648 to +2,147,438,647
long int 4 2,147,438,648 to +2,147,438,647
long long int 8 9,223,372,036,854,775,808 to +9,223,372,036,854,775,807
float 4 ±3.4E38 (6 decimal digits precision)
double 8 ±1.7E308 (15 decimal digits precision)
long double 12 ±1.19E4932 (18 decimal digits precision)

also there’s an unsigned variable for every variable (eg. unsigned int) , the difference will be in the range (starting from 0) .
there’s also boolean variables which take a value of true or false .
Note : when you try to declare a variable of type boolean it’ll be like this :

  • _Bool isTrue = true;
  • or you put a header (#include<stdbool.h>) then you declare the variable  (bool isTrue= true;)

 
if we want to know the ranges of the variable types , simply we write this code :
#include<stdio.h>
#include<limits.h>
int main(void){
printf(“the char variable type ranges between %d and %d “,CHAR_MIN , CHAR_MAX);
return 0;
}
 
let’s examine this code ,

  •  it included stdio.h , limits.h headers (limits.h has the limits of the variable types)
  • it shows the range of char variable type (CHAR_MIN , CHAR_MAX)

the output of running this code will be : the char variable type ranges between -128 and 127
there’s also INT_MIN , INT_MAX , LONG_MIN , LONG_MAX ,  …
now , I want to make a simple code that print the sum of two numbers , here’s the code :
 
#include<stdio.h>
int main(void) {
int num1;
int num2;
printf(“enter the first number”);
scanf(“%d”,&num1);
printf(“enter the second number”);
scanf(“%d”,&num2);
printf(“the result is %d \n” , num1+num2);
}
I guess you noticed that there’s a new term  “scanf” , this function takes the input from the user and stores it in the variable pointed to “we’ll cover that later” .
there’s also some arithmetic operations , like :

  • power “pow(number , power)”
  • square roots “sqrt(number)”
  • exponential”exp(x)”
  • and so on ( just put this header “#include<math.h>”  )

Now , with the end of this article I’d like to put a task
make a program to take the input of two numbers and print their sum , difference , multiplication , division , number one power number two and the square root of every one (you can put your code in the comments) .