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Range of Integers in C++

BY u6dwl
August 24, 2025
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Class Notes: Range of Integers

Introduction

  • Welcome to Nesso Academy.
  • Previous lecture covered the importance of data types in C++.
  • Current lecture focuses on understanding and deriving the formula for the range of integers.
  • Importance: In future lectures, we will discuss fundamental data types and their ranges.

Objective

  • Learn to calculate the range of integers.

Topics Covered

  • Deriving the Formula for Integer Range:

    • Consider a simplified integer data type of size three bits.
    • Calculate range through binary numbers and their combinations:
      • Possible binary combinations: 000, 001, 010, 011, 100, 101, 110, 111
      • Interpretation as positive integers: 0 to 7.
    • Explanation for derivation:
      • Positional weighting of bits: 4, 2, and 1.
      • Example calculation: 111 becomes 4 + 2 + 1 = 7.
  • Range for Both Positive and Negative Integers:

    • Sign bit representation:
      • 0 indicates positive, 1 indicates negative.
    • Formula for range:
      • Using three bits, range is -4 to +3.
    • Derivation for range:
      • Formula: -2^(n-1) to 2^(n-1) - 1.
      • Example conversion for three bits yield above range.

Formula Summary

  • Positive Values Range:
    • General formula for n bits: 0 to 2^n -1.
  • Both Positive and Negative Values Range:
    • General formula for n bits: -2^(n-1) to 2^(n-1) - 1.

Conclusion

  • Successfully derived formulas to calculate the range of integers.
  • Next lecture will cover fundamental data types in C++.

Next Steps

  • Prepare for understanding fundamental data types and their applications in C++ in the upcoming session.

[Applause] [Music]

    Range of Integers in C++