Default negative Numbers to Zero using JavaScript

Borislav Hadzhiev

Last updated: Dec 23, 2021

Photo from Unsplash

**Use the Math.max() function to default negative numbers to zero, e.g.
Math.max(-5, 0). The Math.max() function takes two or more numbers as
parameters and returns the largest of the provided numbers.**

index.js

`const num1 = Math.max(-5, 0); console.log(num1); // 👉️ 0 const num2 = Math.max(10, 0); console.log(num2); // 👉️ 10`

The Math.max function takes two or more numbers as parameters and returns the largest.

By passing zero as a parameter to the function, we can be sure that the min value the function returns will be

`0`

.If on the other hand the number is greater than zero, the `Math.max`

function
will return the number as is.

An alternative solution is to use the ternary operator.

index.js

`let num = -5; num = num < 0 ? 0 : num; console.log(num); // 👉️ 0`

The
ternary operator
is very similar to an `if/else`

statement.

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

The truthy values are all values that are not falsy.

The falsy values in JavaScript are `null`

, `undefined`

, `false`

, `0`

, `""`

(empty string), `NaN`

(not a number).

In our particular example, if the

`num`

variable stores a number that is less than `0`

, the expression before the question mark returns `true`

, so we return`0`

.If the expression returns `false`

, we return the number stored in the `num`

variable.

While this solution is intuitive, I find it a bit harder to read than using the
`Math.max`

method.

An alternative approach is to use a simple `if`

statement.

index.js

`let num = -5; if (num < 0) { num = 0; } console.log(num); // 👉️ 0`

Declaring the `num`

variable with the `let`

keyword allows us to reassign it if
the stored value is less than `0`

.

While this approach is a little more verbose, it's still easy to read and intuitive.