Code Marathi Logo

Assigning Values

3 min read ·

Declaring a variable creates space in memory. Assigning a value means putting actual data inside that variable.
In Java, we use the assignment operator:
The value on the right side gets stored in the variable on the left side.

Basic Syntax

Example:
Here:
  • age is already declared.
  • 25 is assigned to age.

Complete Runnable Example

Output:
25

Declaration + Assignment Together

In real programs, we usually declare and assign in a single line.
Example:
This is the most commonly used style.

Assigning Different Data Types

1️⃣ Integer (int)

Whole numbers only.

2️⃣ Decimal (double)

Decimal values allowed.

3️⃣ Character (char)

  • Must use single quotes
  • Only one character allowed
Wrong:

4️⃣ String

  • Must use double quotes
Wrong:

Re-Assigning Values

Variables can change their value later in the program.
Output:
50 80
The old value gets replaced.

Assigning One Variable to Another

Output:
10
Here, b gets a copy of a.

Assigning Expressions

You can assign calculated values.
Output:
15
Java first calculates the expression, then assigns the result.

Multiple Assignments in One Line

Output:
100 100 100
Java assigns from right to left.

Common Mistakes Beginners Make

❌ Using == Instead of =

== is comparison operator, not assignment.
Correct:

❌ Not Matching Data Types

Because 10.5 is decimal.
Correct:
Assigning values is where variables actually become useful. Without assignment, variables are just empty containers. With assignment, they start storing real data and power your program logic.