Chapter 3: Control Structures Summary

Chapter 3: Control Structures

Objectives

  • Understand and apply conditional statements: if, if-else, if-elif-else.
  • Develop programs to handle multiple conditions.
  • Implement iteration statements: for loops and while loops.

Conditional Statements

  • Need for Conditional Statements: Manage program execution based on conditions.
    • Check a condition.
    • Execute code block if True; skip if False.

IF Statements

  • Syntax: if expression: statement1
  • Executes statements if the condition is true; skips if false.
  • Indentation crucial: same indent indicates a block of statements.

IF ELSE Statements

  • Syntax: if expression: statement1 else: statement2
  • Executes statement1 if true; otherwise, executes statement2.

IF ELIF ELSE Statements

  • Syntax: if expression1: statement1 elif expression2: statement2 ... else: statement n
  • Allows testing multiple conditions sequentially.

Nested IF ELSE

  • If a condition inside another condition must be checked, use nested if.

Iteration Statements

  • Need for Iteration: Perform repetitive tasks until a condition changes.

WHILE Statements

  • Syntax: while expression: statement1
  • Executes statements while the condition is True.

FOR Loop Statements

  • Syntax: for variable_name in list_name: body of loop
  • Iterates through elements in a given list.

The RANGE() Function

  • Generates a sequence of numbers: range(start, end, step).
  • range(n) produces numbers from 0 to n-1.

BREAK and CONTINUE Statements

  • Break: Exits the loop immediately.
  • Continue: Skips to the next iteration of the loop.

PASS Statement

  • Does nothing; serves as a placeholder.

NESTED Loop

  • A loop inside another loop, used for multidimensional arrays like matrices.