Python While Loops Explained

Day 16 / 30 - while Loops in Python What is a while Loop? A while loop keeps running its block of code as long as a condition is True. Unlike a for loop which runs a fixed number of times, a while loop runs an unknown number of times, it stops only when the condition becomes False. Perfect for situations where you don't know in advance how many repetitions you'll need. Syntax Breakdown while condition: # runs as long as condition is True # must update something to eventually make condition False while --> checks the condition before every single run condition --> any expression that evaluates to True or False How It Works, step by step Python checks the condition at the top of the loop If True --> it runs the indented block of code Goes back to the top and checks the condition again Keeps repeating until the condition becomes False When False --> exits the loop and continues the program for Loop vs while Loop for loop 1. Use when you know how many times to repeat 2. Looping over a list, range, sequence while loop 1. Use when you don't know how many times 2. Keep going until a condition changes The Infinite Loop -Most Common Mistake If your condition never becomes False, the loop runs forever, freezing your program. Always make sure something inside your loop changes the condition like incrementing a counter or taking user input so the loop can eventually stop. break and continue break - stops the loop immediately, exits even if the condition is still True continue → skips the current iteration and jumps back to the condition check Both break and continue work in for and while loops. Code Example # Count from 1 to 5 count = 1 while count <= 5: print("Count: " + str(count)) count = count + 1 # break — stop early number = 0 while number < 10: if number == 5: break # stops loop at 5 print(number) number += 1 Key Learnings ☑ A while loop runs as long as its condition is True , checks before every iteration ☑ Always update something inside the loop, counter, input, or flag or you'll get an infinite loop ☑ break exits the loop immediately when a condition is met ☑ continue skips the current iteration and jumps back to the condition check ☑ Use for when you know the count — use while when you don't Why It Matters While loops power real systems — PIN verification, login retry limits, game loops, servers waiting for requests. Anywhere your program needs to wait or keep trying until something changes, a while loop is the answer. My Takeaway A for loop is like a to-do list — you know how many items there are. A while loop is like waiting for a bus — you keep waiting until it arrives. Different tools, different situations. #30DaysOfPython #Python #LearnToCode #CodingJourney #WomenInTech

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