📜 WAYPOINT LESSON

Variables, Declaration & Assignment

⭐ beginner⏳ 10 min read📍 Lesson 4 of 225

A variable is a named box of memory. Declaration creates it, assignment replaces its content, initialization does both at once.

Boxes with names

A variable is a named region of memory holding a value of one type.

int score;          // declaration: box exists, content UNSET
score = 42;         // assignment: put 42 in the box
int lives = 3;      // declaration + initialization together

Reading an uninitialized variable is undefined behavior. The compiler may warn; the program may print garbage. Rule: initialize on declaration whenever you can.

Assignment replaces

int x = 1;
x = 2;      // x is now 2; the 1 is gone
x = x + 5;  // right side computed first: 2 + 5 = 7
x += 5;     // shorthand for x = x + 5

Assignment is not equality — it is a command: "evaluate the right side, store it into the left side".

Multiple variables

int a = 1, b = 2;   // legal but style prefers one per line

⚡ Now practice

Ready to Code

Value SurgeryDeclare, assign, and re-assign — prove you know what each variable holds at the end.

3 challenges · · ~14 min