C Variable Values: Modifying and Overwriting Data

Understanding how to manage variable values is essential in C programming. When you assign a new value to an existing variable, it effectively overwrites the previous value. This section will delve into how to change variable values in C, demonstrating the process of data manipulation in your programs.

C Variable Values

Change Variable Values

When you assign a new value to an existing variable, it overwrites the previous value:

int myNum = 15;  // myNum is 15
myNum = 10;      // Now myNum is 10

You can also assign the value of one variable to another:

int myNum = 15;
int myOtherNum = 23;

// Assign the value of myOtherNum (23) to myNum
myNum = myOtherNum; // myNum is now 23

printf("%d", myNum);

Output

23

You can also copy values to uninitialized variables:

// Create a variable and assign the value 15 to it
int myNum = 15;

// Declare a variable without assigning it a value
int myOtherNum;

// Assign the value of myNum to myOtherNum
myOtherNum = myNum; // myOtherNum now has 15 as a value

printf("%d", myOtherNum);

Output

15

Add Variables Together

To add one variable to another, use the + operator:

int x = 5;
int y = 6;
int sum = x + y;

printf("%d", sum);

Output

11