Iteration - AP Computer Science Principles

Iteration is the repetition of a block of code multiple times. It's a fundamental programming concept for repeating tasks.

A 'for' loop is a common loop structure. It iterates over sequences or a specified range.

The 'while' keyword starts a 'while' loop. It's the standard syntax for conditional loops in Python.

The loop variable iterates through a sequence. It takes on each value from the sequence being looped over.

A 'for' loop is best for iterating a known number of times. It allows precise control over the number of iterations.

A 'while' loop continues until a condition is false. It evaluates the condition before each iteration.

An infinite loop runs indefinitely without terminating. Usually occurs when the termination condition is never met.

The 'break' statement exits a loop prematurely. It immediately terminates the loop regardless of condition.

The 'continue' statement skips to the next iteration. It bypasses remaining code in the current iteration.

No error; it prints numbers 1 to 4. The syntax is correct and executes properly.

Error: Missing colon after 'True'. Python requires a colon after the condition.

Iterates with values 0, 1, 2. Single argument creates sequence from 0 to n-1.

'while condition:'. This is the proper Python while loop syntax.

An iterator provides access to elements in a collection. It enables sequential access to data structures.

No error; it prints 1, 2, 3. The syntax correctly iterates over the list.

Iterates over 0, 2, 4. The step parameter of 2 skips every other number.

Prints 'Hi' twice. The loop executes twice with range(2).

Outputs 5, 4, 3, 2. Negative step creates descending sequence.

No error; it prints 0, 1, 2. The syntax is valid and executes correctly.

'Break' exits the loop immediately. It terminates the loop completely.

A 'for' loop is used for iterating over a sequence. It processes each element in the sequence.

Skips the current iteration and continues with the next. It jumps directly to the next loop iteration.

'range()' provides a sequence of numbers to iterate over. It generates sequences without manual counting.

for i in range(1, 6): print(i). This creates a sequence from 1 to 5 inclusive.

Continues as long as the condition is true. It evaluates the condition before each iteration.

'pass' acts as a placeholder and does nothing. It prevents syntax errors in empty code blocks.

'for element in list:' allows iteration over list elements. This syntax directly accesses each list element.

Prints 4, 3, 2. Negative step counts down from 4 to 2.

Outputs nothing. False condition prevents any loop execution.