Bit Manipulation Basics AND OR XOR NOT Left Right Shift in DSA Typescript - Practice Problems & Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of Bitwise AND and OR Operations

What is the output of the following TypeScript code?

const a = 5;  // binary 0101
const b = 3;  // binary 0011
const andResult = a & b;
const orResult = a | b;
console.log(andResult, orResult);

DSA Typescript

const a = 5;  // binary 0101
const b = 3;  // binary 0011
const andResult = a & b;
const orResult = a | b;
console.log(andResult, orResult);

A 1 6

B 1 7

C 0 7

D 0 6

💡 Hint

Remember how AND and OR work bit by bit.

AND compares each bit: 0101 & 0011 = 0001 (1). OR compares each bit: 0101 | 0011 = 0111 (7).

❓ Predict Output

intermediate

Result of XOR and NOT Operations

What will be printed by this TypeScript code?

const x = 12;  // binary 1100
const y = 10;  // binary 1010
const xorResult = x ^ y;
const notResult = ~x;
console.log(xorResult, notResult);

DSA Typescript

const x = 12;  // binary 1100
const y = 10;  // binary 1010
const xorResult = x ^ y;
const notResult = ~x;
console.log(xorResult, notResult);

A 2 13

B 6 13

C 6 -13

D 2 -13

💡 Hint

XOR is 1 when bits differ. NOT flips all bits and changes sign.

XOR: 1100 ^ 1010 = 0110 (6). NOT 12 (00001100) flips bits to 11110011 which is -13 in two's complement.

❓ Predict Output

advanced

Left and Right Shift Effects

What is the output of this TypeScript code?

let num = 7;  // binary 00000111
const leftShift = num << 2;
const rightShift = num >> 1;
console.log(leftShift, rightShift);

DSA Typescript

let num = 7;  // binary 00000111
const leftShift = num << 2;
const rightShift = num >> 1;
console.log(leftShift, rightShift);

A 28 3

B 28 6

C 14 3

D 14 6

💡 Hint

Left shift multiplies by 2 twice, right shift divides by 2 once.

7 << 2 = 7 * 4 = 28. 7 >> 1 = floor(7 / 2) = 3.

🔧 Debug

advanced

Identify the Error in Bitwise NOT Usage

What error or unexpected behavior occurs when running this TypeScript code?

const val = 0;
const result = ~val;
console.log(result);

DSA Typescript

const val = 0;
const result = ~val;
console.log(result);

A Prints 0 because NOT of zero is zero

B Prints 1 because NOT flips bits to 1

C Throws a TypeError because ~ is invalid on numbers

D Prints -1 due to two's complement representation

💡 Hint

Think about how NOT works on binary numbers and two's complement.

NOT flips all bits. For 0 (all zeros), ~0 is all ones which is -1 in two's complement.

🧠 Conceptual

expert

Effect of Right Shift on Negative Numbers

In TypeScript, what is the output of this code?

const neg = -8;  // binary representation in two's complement
const shifted = neg >> 2;
console.log(shifted);

DSA Typescript

const neg = -8;  // binary representation in two's complement
const shifted = neg >> 2;
console.log(shifted);

A -2

B 2

C -3

D 3

💡 Hint

Right shift on negative numbers keeps the sign bit (arithmetic shift).

Right shifting -8 (11111000) by 2 keeps sign bits, resulting in -2.

Practice

1. What is the result of the bitwise AND operation between 5 and 3? (5 = 0101, 3 = 0011 in binary)

easy

A. 1

B. 7

C. 6

D. 0

Solution

1. Step 1: Convert numbers to binary

   5 in binary is 0101, 3 in binary is 0011.

2. Step 2: Perform bitwise AND operation

   0101 AND 0011 = 0001 (only bits set in both numbers remain set).

3. Final Answer:

   1 -> Option A

4. Quick Check:

   5 & 3 = 1 [OK]

Hint: AND keeps bits set in both numbers only [OK]

Common Mistakes:

• Confusing AND with OR operation
• Not converting numbers to binary before operation
• Assuming decimal addition instead of bitwise operation

2. Which of the following is the correct TypeScript syntax to perform a bitwise XOR between variables a and b?

easy

A. let result = a && b;

B. let result = a % b;

C. let result = a | b;

D. let result = a ^ b;

Solution

1. Step 1: Identify bitwise XOR operator in TypeScript

   The bitwise XOR operator is the caret symbol (^).

2. Step 2: Check each option for correct syntax

   let result = a ^ b; uses ^ correctly. let result = a && b; uses logical AND (&&), let result = a | b; uses bitwise OR (|), let result = a % b; uses modulus (%).

3. Final Answer:

   let result = a ^ b; -> Option D

4. Quick Check:

   Bitwise XOR uses ^ operator [OK]

Hint: XOR operator is ^ in TypeScript [OK]

Common Mistakes:

• Using logical operators instead of bitwise
• Confusing OR (|) with XOR (^)
• Using modulus operator (%) by mistake

3. What is the output of the following TypeScript code?

const x = 8; // binary 1000
const y = x >> 2;
console.log(y);

medium

A. 0

B. 2

C. 1

D. 4

Solution

1. Step 1: Understand right shift operation

   Right shift (>>) moves bits to the right by the specified number, dropping rightmost bits.

2. Step 2: Apply right shift to 8 (1000 binary)

   Shifting 1000 right by 2 bits gives 0010 binary, which is 2 in decimal.

3. Final Answer:

   2 -> Option B

4. Quick Check:

   8 >> 2 = 2 [OK]

Hint: Right shift divides by 2 for each shift [OK]

Common Mistakes:

• Confusing right shift with left shift
• Not converting binary to decimal after shift
• Assuming shift adds zeros on left without dropping bits

4. Identify the error in this TypeScript code snippet:

let a = 5;
let b = 3;
let c = a <<< b;
console.log(c);

medium

A. <<< is not a valid bitwise operator

B. Variables a and b must be strings

C. Missing semicolon after variable declarations

D. Bitwise operators cannot be used with let variables

Solution

1. Step 1: Check the bitwise operators in TypeScript

   Valid bitwise shift operators are << (left shift) and >> (right shift). There is no <<< operator.

2. Step 2: Identify the invalid operator usage

   The code uses <<< which is invalid syntax and will cause an error.

3. Final Answer:

   <<< is not a valid bitwise operator -> Option A

4. Quick Check:

   Only << and >> are valid shift operators [OK]

Hint: Use only << or >> for shifts, not <<< or >>> [OK]

Common Mistakes:

• Using triple shift operator like in some other languages
• Assuming semicolons are mandatory for correctness
• Thinking bitwise operators require specific variable types

5. Given n = 29 (binary 11101), which expression will toggle the 3rd bit (counting from 0 at right) using bitwise XOR in TypeScript?
Choose the correct code snippet.

hard

A. let result = n | (1 << 3);

B. let result = n & (1 << 3);

C. let result = n ^ (1 << 3);

D. let result = ~n ^ (1 << 3);

Solution

1. Step 1: Understand toggling a bit with XOR

   XOR with 1 flips the bit; XOR with 0 leaves it unchanged.

2. Step 2: Create mask for 3rd bit

   1 << 3 shifts 1 to the 3rd bit position (binary 1000).

3. Step 3: Apply XOR to toggle the bit

   n ^ (1 << 3) flips the 3rd bit of n.

4. Final Answer:

   let result = n ^ (1 << 3); -> Option C

5. Quick Check:

   XOR with mask toggles bit [OK]

Hint: XOR with 1 at bit toggles it, 0 leaves it same [OK]

Common Mistakes:

• Using AND or OR instead of XOR to toggle bits
• Incorrect bit position shift
• Using NOT operator incorrectly with XOR