Get the Difference between Two Numbers in JavaScript

# Get the difference between Two Numbers in JavaScript

To get the difference between two numbers, subtract the first number from the second and pass the result to the Math.abs() method.

The Math.abs() method returns the absolute value of a number.

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function getDifference(a, b) {
  return Math.abs(a - b);
}

console.log(getDifference(10, 15)); // 👉️ 5
console.log(getDifference(15, 10)); // 👉️ 5
console.log(getDifference(-10, 10)); // 👉️ 20

The Math.abs() method returns the absolute value of a number.

In other words, it returns the number's distance from zero.

Here are some examples:

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console.log(Math.abs(-3)); // 👉️ 3
console.log(Math.abs(-3.5)); // 👉️ 3.5
console.log(Math.abs(-0)); // 👉️ 0
console.log(Math.abs(3.5)); // 👉️ 3.5
console.log(Math.abs('-3.5')); // 👉️ 3.5

The Math.abs() method returns the provided number if it's positive or zero and the negation of the number if it's negative.

An alternative approach is to use an if statement.

# Get the Difference between Two Numbers using an if statement

This is a two-step process:

1. Use an if statement to check which number is greater.
2. Subtract the lower number from the greater number.

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function getDifference(a, b) {
  if (a > b) {
    return a - b;
  }

  return b - a;
}

console.log(getDifference(10, 15)); // 👉️ 5
console.log(getDifference(15, 10)); // 👉️ 5
console.log(getDifference(-10, 10)); // 👉️ 20

The if statement checks if the first number is greater than the second.

If the condition is met, we subtract the lower number from the greater and return the result.

Otherwise, we know that the numbers are equal or the second number is greater, so we do the inverse.

The code sample could also be shortened by using a ternary operator.

# Get the difference between two numbers using a ternary operator

This is a two-step process:

1. Use the ternary operator to determine which number is greater.
2. Subtract the lower number from the greater number and return the result.

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const a = 10;
const b = -20;

const difference = a > b ? a - b : b - a;

console.log(difference); // 👉️ 30

The ternary operator is very similar to an if/else statement.

If the expression to the left of the question mark is truthy, the operator returns the value to the left of the colon, otherwise, the value to the right of the colon is returned.

If you have to do this often, define a reusable function.

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function getDifference(a, b) {
  return a > b ? a - b : b - a;
}

console.log(getDifference(10, 15)); // 👉️ 5
console.log(getDifference(15, 10)); // 👉️ 5
console.log(getDifference(-10, 10)); // 👉️ 20

The getDifference() function takes 2 numbers as parameters and returns the difference between the numbers.

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

• Get the Decimal Part of a Number in JavaScript
• Get Difference between two Arrays of Objects in JavaScript
• Get the Difference between Two Arrays in JavaScript
• Get the Difference between Two Sets using JavaScript