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.