Change and Use Variables in C

1. Changing Variable Values

Once you create a variable, you can change (update) its value later in the program.
When a new value is assigned, it overwrites the previous one.

Example:

int myNum = 15;  // myNum is 15

myNum = 10;      // Now myNum becomes 10

printf(“%d”, myNum);

✅ Output:

10

👉 Explanation:
The first value (15) is replaced by the new value (10).

2. Assign One Variable’s Value to Another

You can assign (copy) the value of one variable to another.

Example:

int myNum = 15;

int myOtherNum = 23

// Assign value of myOtherNum (23) to myNum

myNum = myOtherNum;

printf(“%d”, myNum);

✅ Output:

23

👉 Explanation:
myNum took the value of myOtherNum, so myNum is now 23

3. Copy Values into Empty Variables

You can also assign a value from one variable to another empty variable.

Example:

int myNum = 15;

int myOtherNum

myOtherNum = myNum;  // Copy valu

printf(“%d”, myOtherNum);

✅ Output:

15

4. Add Variables Together

You can perform math operations with variables — like addition, subtraction, multiplication, etc.

Example:

int x = 5;

int y = 6;

int sum = x + y;

printf(“%d”, sum);

✅ Output:

11

 Quick Summary