How do you compare three variables in javascript?

Compare 3 Values in JavaScript #

To compare 3 values, use the logical AND [&&] operator to chain multiple conditions. When using the logical AND [&&] operator, all conditions have to return a truthy value for the if block to run.

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const value1 = 10;
const value2 = 10;
const value3 = 10;

if [value1 === value2 && value2 === value3] {
  // 👇️ this runs
  console.log['✅ all 3 values are equal'];
} else {
  console.log['⛔️ values are NOT equal'];
}

In the code example, we used the logical AND [&&] operator to chain two conditions.

When using the logical AND [&&] operator in an if statement, all conditions have to be met for the if block to run.

The logical AND [&&] operator returns the value to the left if it's falsy, otherwise it returns the value to the right.

The falsy values in JavaScript are: false, null, undefined, 0, "" [empty string], NaN [not a number]. All other values are truthy.

This means that if the conditions on both sides of the logical AND [&&] operator evaluate to a value other than the aforementioned 6, the if block is run.

If our example we check if the 3 values are equal. Since the conditions on both sides of the operator return true, the if block is run.

First, the condition on the left of the && is evaluated, if it returns a falsy value, the condition on the right-hand side is not evaluated at all and the else block is run.

Let's look at another example.

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const value1 = 10;
const value2 = 10;
const value3 = 20;

if [value1 === value3 && value2