C lang is easy to understand. Only what matters is the way you see it. In C, all variables must be declared before they can be used. In other words, you should tell the compiler to associate a type with each variable  let see the following program.

#include <stdio.h>
int main (void)
{
        int x, y, r;
        int const vj = '55';
        float w = 7;
        float f = 4;
}

 variables- x, y,r,w,f and the constant -vj. We also initialized the values of variables w and f to 7 and 4 respectively, and the value of vj to 55. Declaration statement for a variable looks like

type_variable type_name;

 To declare a constant you should add the word const after or before the type of the constant. The following declarations are identical.

variable_type const variable_name;
const variable_type variable_name;

The most fundamental data types   in C are:

• integral types

• floating types

• arithmetic types

The integral types are designed for working with the integer values.

• char, signed char, unsigned char

• short, int, long

• unsigned short, unsigned int, unsigned long

  The data type int is the principle working type of the C language. For example

int no_of_kids = 50;