Boolean Logic in Programming: Expressions, Operators, and Syntax for Beginners

Q: What is the difference between = and == in programming?

The = is for assigning variables, while == is for performing a Boolean logic test to see if the two sides are equal.

Q: What is Boolean logic in real life?

Boolean logic in real life is a voltage in a wire. Our article about understanding binary numbers covers this concept.

Posted on May 28, 2025 by Boden Bensema

Concept Programming Boolean Logic

Boolean logic is fundamental in computer programming, forming the basis of control flow, conditions, and decision-making in all major programming languages. That's what makes understanding how Boolean logic is used in programming and what Boolean logic is an important concept when understanding computer science. Whether working with data in Python, creating a game in Java, or simply trying to expand your knowledge, this article will help you understand Boolean logic in code with simple terms and concepts.

Boolean expression basics

Boolean expressions are equations that can be evaluated down to one of two states: true or false. Either the expression is true, or it is false. For example,

1 + 1 = 2

Is true. However,

1 + 1 = 3

Is false. To break it down, notice that there in both expressions, there is a "=” sign. This sign separates the logical expression into two parts. For the first example, it separates "1 + 1” and "2”. Because the sign separating the two means "equals,” we can put this expression into words:

One plus one equals two.

This is a true statement. Boolean logic would evaluate the statement and return true. After evaluating a statement, we only care about the resulting true or false given by the Boolean output.

Boolean expressions can also use greater than or less than signs to return a true or false statement. By altering the above example two, we can say

 1 + 1 < 3

After evaluating the boolean expression, we would get an output of true.

Boolean expressions don't only use integers. Boolean expressions can also use strings. The following expression would output true:

 "this text" = "this text"

This returns true because each character in the string on the left perfectly matches each character in the string on the right.

Applying Boolean expressions in code

What we have been dealing with is called equalities (=) and inequalities (> or <). All programming languages have different syntax, but there is a symbol that is most widely used in Java, C, C++, JavaScript, C#, Swift, Kotlin, Python, Ruby, PHP, Go, Rust, Perl, Scala, Dart, and Julia. For equalities, they all use the symbol "==”. In practice, this looks like

 1 == 1

And this statement would be true. For inequalities, they use > for greater than, < for less than, >= for greater than or equal to, and <= for less than or equal to. An example for each of these:

 1 < 2 
    returns true

 2 <= 2 
    returns true

 4 > 3 
    returns true

 4 >= 4 
    returns true

How to use Boolean operators

Boolean operators are very important when understanding how to code. Three Boolean operators are most commonly used in coding: the AND, NOT, and OR operators. These most common Boolean operations can cover pretty much every operation you will need to accomplish when programming. Let's take a look at how to use Boolean operators in code.

AND Operator

Most programming languages (C, C++, Java, JavaScript, C#, Go, Swift, Kotlin, Rust) use && for their AND operator. However, some languages like Python, Ruby, and Lua use the word "and". To clear this up, here's a chart with the programming languages and their way of showing the Boolean operators:

Different languages all use basic Boolean logic in programming, but there are different ways of representing this.

Let's dive into using this Boolean operator in code.

For the majority of programming languages, using the AND operator would look like this:

 true && false 
    returns false; AND requires all inputs to be true

The other languages look like this:

 true and true 
    returns true; all inputs are true

The reason some coding languages use symbols and some use words is simply for human readability. Python is usually a beginner's programming language, so they most likely wanted to increase its readability for its purpose.

OR Operator

Like AND, many programming languages use || for their logical OR operation, but Python, Ruby, and Lua use the literal word "or”. The OR operator's usage is exactly similar to the AND operator's, but with a different symbol and output. For the majority, you would write

 true || false 
    returns true; Only one input has to be true

For Python, Ruby, and Lua, it is very similar; the only difference is the change of the symbol:

 false or false 
    returns false; no inputs are true

It is the same operator, but with a different representation.

NOT Operator

Following the trend, NOT is symbolized by a "!" in most languages, but in Python, Ruby, and Lua, you perform the NOT operation with the word "not”. NOT, being the only Boolean operator with one input, is slightly different than the other two operators above. This operator, in Java and the rest, looks like this:

 !true 
    returns false, as the opposite of true is false

And in Python, Ruby, and Lua:

 not true
    returns false again

Conclusion

Boolean logic is a core concept in programming languages, enabling decision-making and control flow through simple true/false evaluations. Whether using && and || in Java, or and and or in Python, all modern programming relies heavily on boolean expressions. Mastering these fundamentals helps you write cleaner, smarter, and more logical code—an essential skill for beginners in software development.