How to Efficiently Get a Bit Value from a Truth Table in Java, JS, and TS

Discover a quick formula for retrieving bit values from a truth table for any given row and column in Java, JavaScript, or TypeScript.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Java/JS/TS Given row and column get bit value in truthtable

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding Bits in a Truth Table

When working with truth tables, you might find yourself frequently needing to access a specific bit value based on its row and column. This is especially common when dealing with large data sets and efficiency is key. For instance, a frequent question is, "How can I quickly determine the bit value for a given row and column?" This guide aims to provide a concise solution that is both efficient and easy to understand.

The Problem

Imagine you are given a binary representation in a truth table format, like the following:

[[See Video to Reveal this Text or Code Snippet]]

Your goal is to find the bit value for a specific row and column without converting the entire number to a bit array, especially when working with large numbers. For example, for getTTBit(row = 3, col = 2), the expected output is 1.

The Solution

Efficient Access to Bit Values

The core question you're tackling is how to check if the Nth bit is set in a number. Luckily, there's a very efficient method to achieve this using bitwise operations in multiple programming languages, including Java, JavaScript (JS), and TypeScript (TS).

Bitwise Operation

[[See Video to Reveal this Text or Code Snippet]]

This line of code achieves the following:

row: The current row number for which you want to check the bit.

col: The column number (starting from 0 on the right).

1 << col: This expression shifts the number 1 left by col positions in binary format, essentially creating a binary mask. For example, if col is 2, the mask would be 000...100 in binary.

& (Bitwise AND): This operator checks if the specified bit is set. If the result is not 0, it means the bit is indeed set (or 1).

Step-by-Step Breakdown

Determine the Column: Start with your column number; remember that counting begins from the right (with 0 as the least significant bit).

Create a Mask: Shift 1 left by the column index using (1 << col).

Apply the Bitwise AND: Use the & operator to check if the specified bit in the row number is set.

Check the Result: If the result of the & operation is not zero, the bit is set; otherwise, it is not.

Example Implementation

Here’s a quick TypeScript function utilizing the above logic:

[[See Video to Reveal this Text or Code Snippet]]

In this function:

It directly checks if the bit at position col is set in the row.

Returns 1 if the bit is set; otherwise, it returns 0.

Conclusion

By using the bitwise operation method outlined above, you can efficiently access specific bit values in a truth table without the overhead of converting rows to arrays. This approach is beneficial, especially when handling large datasets, making your operations faster and simpler.

Now you have a powerful tool at your disposal to work with bit values in truth tables, making coding in Java, JavaScript, or TypeScript easier and more efficient. Enjoy coding and exploring more bit-related operations!