> For the complete documentation index, see [llms.txt](https://codehs.gitbook.io/introcs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://codehs.gitbook.io/introcs/basic-javascript-and-graphics/comparison-operators.md).

# Comparison Operators

Comparison operators allow us to compare two values against one another. A comparison returns a boolean result of either **true** or **false**. The table below lists each of the comparison operators and their usages:

| Operator | Usage                    |
| -------- | ------------------------ |
| >        | Greater Than             |
| <        | Less Than                |
| >=       | Greater Than Or Equal To |
| <=       | Less Than Or Equal To    |
| ==       | Equal To                 |
| !=       | Not Equal To             |

## A Basic Comparison

In the following example, we compare two variables `x` and `y`. We store the result of this comparison in variable `z`.

```
var x = 10;
var y = 8;

var z = x > y;
println(z);
```

What will get printed to the screen? The above comparison, x > y, is evaluating if 10 is greater than 8. Because 10 is indeed greater than 8, `z` is assigned a value of true. Thus, `true` will get printed to the screen.

## More Practice

Let's get a little more practice. Take a look at the following code segment below. Pay close attention to each comparison and the operator being used.

```
var a = 3;
var b = 5;
var c = 2;
var d = 3;

var t = a > 0;
var u = a == d;
var v = d >= b;
var w = b > c;
var x = a != d;
var y = d < = a;
var z = 4 < = c;
```

```
println("t = " + t);
println("u = " + u);
println("v = " + v);
println("w = " + w);
println("x = " + x);
println("y = " + y);
println("z = " + z);
```

When we run this code, what boolean values (**true** or **false**) will get printed to the screen for variables t through z? See if you can figure it out on your own. The solution is given below.

### Solution:

```
t = true
u = true
v = false
w = true
x = false
y = true
z = false
```

## Comparison Operators in a Program

Suppose we want to write a program which restricts people under a certain height from riding on a roller coaster. For this particular roller coaster, people who are under 4 feet (48 inches) are not allowed on the ride. How would we do this?

```
var height = readInt("How tall are you (in inches)? ");
var isTallEnough = height >= 48;
println("Can ride on the roller coaster: " + isTallEnough);
```

## Pitfalls

A common mistake is using `=` when you actually want to use `==`. `=` is used for assignment of variables whereas `==` is used for comparing the equality of two values.

For example, `x = 5` stores the value `5` into the variable `x`. However, `x == 5` tests to see if the value `5` is equal to the variable `x` and then returns either true or false. **They are not the same thing!**