While Loops and Arrays in Python

Valid While Loops

• Valid while loop example: x = 1; while x <= 5: x += 1
• This loop initializes x to 1 and continues as long as x is less than or equal to 5

Array Declarations

• Valid array declaration: arr = array.array('i', [1, 2])
• Invalid array declaration: a = arr.array('i', [12])

Printing Array Values

• Valid array printing: for n in a: print(n, end=" ")
• Valid array printing (alternative): for n in range(len(a)): print(a[n], end=" ")
• Invalid array printing: for n in range(len(a)): print(n, end=" ")

Printing Array Length

• Valid way to print array length: print(len(a))

Code Output Analysis (Question 6-11)

• Consider the initial array a = [6, 3, 7, 2, 3, 4]
• a.insert(2, 9) inserts 9 at index 2, resulting the new array as [6, 3, 9, 7, 2, 3, 4] will print the updated array elements
• a.append(9) adds 9 to the end of the array, resulting in [6, 3, 7, 2, 3, 4, 9] will print these elements
• a.pop(3) removes element at index 3 (which is 2) from the array, resulting in [6, 3, 7, 3, 4] will print these elements

For Loop Output Analysis (Question 12)

• The output of the code for n in range(2): print("*", end=" "); for m in range(2): print("*", end=" "); print() is ****

While Loop Output Analysis (Question 13-14)

• Output of x=1; while x<=3: print("#", end=' '); x+=1 is # # #
• Output of x=1; while x>=3: print("#", end=' '); x+=1 is empty or nothing

While Loop Conditions Analysis (Question 15-17)

• continue statement skips the rest of the code inside the loop if the condition is met.
• break statement will exit the loop entirely.
• Understanding the if conditions is crucial for determining the output of the while loop logic.

Array Methods (Question 18-19)

• a.index(element) returns the index of the first occurrence of the element in array a.
• Import array as ar is used in question 19.

Array Operations (Question 20-22)

• Array methods like insert(), remove(), append(), and pop() modify the array in-place.
• The loops iterate through the elements of the array a after applying these methods and print the elements
• a.slice() return a sub-array of a from the given index to the end.

Code Completion (Question 23)

• Correct answer depends on which elements the question asks for from the array.

Function Signature (Question 25-27)

• Valid function signature format example: def myFunc(arg1, arg2)

  • Correct Function signature format example: def myFun(argA = 5, argB = 7)

• Invalid format (and examples of why it is invalid): def myFun (argA argB = 7)

Function Output (Question 28-29)

• Function add does a simple addition calculation
• The correct output for question 28 and 29 depends on what the question asks for in term of what will be returned by function.

More Code Outputs (Question 30-33)

• The outputs in these questions are determined by the code's logic, including function calls.

This quiz covers the essentials of valid while loops and array operations in Python. You'll encounter examples of correct and incorrect array declarations, printing techniques, and code output analysis. Test your understanding of these fundamental programming concepts.