To make sure that you always return a negative number in JavaScript, you can do either of the following:
Using Unary Negation Operator
You can convert the number to its absolute form, and then negate it using the unary negation operator (-
):
-Math.abs(n)
This would convert a positive number to negative and ensure that an already negative number remains unchanged. For example, you can use this in the following way:
// ES6+ const neg = (num) => -Math.abs(num); console.log(neg(1234)); // -1234 console.log(neg(-1234)); // -1234
You can rewrite the "neg
" function as a function declaration/statement (instead of using arrow function), to support versions of ES prior to version 6.
Using Arithmetic Operators
You can convert the number to its absolute form, and then negate it either by:
- Multiplying or dividing the number by
-1
, or; - Subtracting the number from
0
.
Math.abs(n) * -1
Math.abs(n) / -1
0 - Math.abs(n)
This would convert a positive number to negative and ensure that an already negative number remains unchanged. For example, you can use these in the following way:
// ES6+ const neg = (num) => Math.abs(num) * -1; console.log(neg(1234)); // -1234 console.log(neg(-1234)); // -1234
// ES6+ const neg = (num) => Math.abs(num) / -1; console.log(neg(1234)); // -1234 console.log(neg(-1234)); // -1234
// ES6+ const neg = (num) => 0 - Math.abs(num); console.log(neg(1234)); // -1234 console.log(neg(-1234)); // -1234
You can rewrite the "neg
" function as a function declaration/statement (instead of using arrow function), to support versions of ES prior to version 6.
This post was published by Daniyal Hamid. Daniyal currently works as the Head of Engineering in Germany and has 20+ years of experience in software engineering, design and marketing. Please show your love and support by sharing this post.