AND, OR, XOR & Shifts
Read and combine bits with confidence.
AND, OR, XOR & Shifts is a free Coding Interview Prep lesson on CoddyKit. This is lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Coding Interview Prep learning path, and your progress syncs across the web and the CoddyKit app. The Coding Interview Prep course includes 4 lessons in total.
Bits Are Your Toolkit
Every integer is really a row of bits, just 0s and 1s. Learning to read and combine them gives you fast, clever tricks in contests. 🔧
See the Binary
Use Python's bin() to peek at the bits of any number. The 0b prefix just marks it as binary, the rest is the bit pattern.
print(bin(13)) # 0b1101AND Keeps Common Bits
The AND operator (&) gives a 1 only where both numbers have a 1. It is perfect for checking or masking shared bits.
print(6 & 3) # 0b110 & 0b011 = 0b010 = 2OR Combines Bits
The OR operator (|) gives a 1 wherever either number has a 1. Use it to switch flags on without disturbing the rest.
print(6 | 1) # 0b110 | 0b001 = 0b111 = 7XOR Spots Differences
The XOR operator (^) gives a 1 where the two bits differ. It is a contest favorite for toggling and finding the odd one out.
print(6 ^ 3) # 0b110 ^ 0b011 = 0b101 = 5XOR Cancels Itself
A number XOR itself is always 0, and XOR with 0 leaves it unchanged. That self-canceling property powers many XOR puzzles.
print(7 ^ 7) # 0
print(7 ^ 0) # 7Find the Unique Number
If every value appears twice except one, XOR them all together and the pairs vanish. What survives is the unique value.
ans = 0
for x in [4, 1, 2, 1, 2]:
ans ^= x
print(ans) # 4Left Shift Multiplies
A left shift pushes bits up, adding zeros on the right. Each shift by one doubles the value, like multiplying by a power of two.
print(3 << 2) # 3 * 4 = 12Right Shift Divides
A right shift drops bits off the right end. Each shift by one halves the value, doing integer division by a power of two.
print(20 >> 2) # 20 // 4 = 5Make a Power of Two
Shifting 1 left by k builds the value 2 to the k instantly. This is the cleanest way to create single-bit masks.
print(1 << 5) # 32Speed Matters in Contests
Bitwise operators run in a single fast step, so swapping arithmetic for shifts can rescue a borderline time limit. Know them cold. ⚡
Quick Check
Time to test your bit operators.
Recap: Bit Operators
You met AND, OR, XOR and shifts: combine, toggle, and scale bits in one fast step. These are the building blocks for every bit trick ahead. 🎉
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Frequently Asked Questions
Is the “AND, OR, XOR & Shifts” lesson free?
Yes — the full text of “AND, OR, XOR & Shifts” is free to read here on the web. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Coding Interview Prep course, upgrade to CoddyKit PRO. The Coding Interview Prep course includes 4 lessons in total.
What will I learn in “AND, OR, XOR & Shifts”?
Read and combine bits with confidence. You practise Coding Interview Prep with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Coding Interview Prep?
No prior experience is required. Coding Interview Prep on CoddyKit is structured for beginners through advanced learners, so you can start here or from the beginning and move at your own pace. This is lesson 1 of 4.
How long does the “AND, OR, XOR & Shifts” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Coding Interview Prep lesson?
Yes. Every Coding Interview Prep lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- AND, OR, XOR & Shifts
- Set, Clear & Toggle a Bit
- Count Bits and Lowest Set Bit
- Bitmasks as Tiny Sets