5 Return Negative

8Kyu Tantangan #5/366 - 05 Feb 2025

https://www.codewars.com/kata/55685cd7ad70877c23000102

5.1 Instruction

In this simple assignment you are given a number and have to make it negative. But maybe the number is already negative?

Examples

make_negative(1);  # return -1  
make_negative(-5); # return -5
make_negative(0);  # return 0

Notes

The number can be negative already, in which case no change is required.
Zero (0) is not checked for any specific sign. Negative zeros make no mathematical sense.

5.2 YouTube Video

5.3 Solution Code

Solusi bar-bar

make_negative <- function(num){
  ifelse(num <= 0, num, -1*num)
}

Solusi simple

make_negative <- function(num)-abs(num)

5.4 Test

library(testthat)

test_that('Basic tests', {
  expect_equal(make_negative(42), -42)
  expect_equal(make_negative(-9), -9)
  expect_equal(make_negative(0), 0)
  expect_equal(make_negative(1), -1)
  expect_equal(make_negative(-1), -1)
})

## Test passed 🎉

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