DEV Community: Rakshith holla

Negative Number to Positive Number without using abs() - asked in a interview

Rakshith holla — Mon, 29 Mar 2021 04:22:26 +0000

In JavaScript, we have a method called absolute - abs() to convert a negative number into positive number.

Usage - Math.abs(-7);

Now, we will see how we can perform the same operation without using the built-in absolute method,

const negativeToPositive = num =>{
  if(num < 0){
    return num * -1;
  }
  return num;
}

console.log(negativeToPositive(-8));

Here we have written a function which based on the input number given, converts the negative number input to positive and for positive number input, it just returns the number.

Hope this was helpful😊.

Swapping two numbers using arithmetic operators

Rakshith holla — Wed, 10 Feb 2021 03:49:51 +0000

We can perform swapping of two numbers without using temp variable and just by using arithmetic operators.

Operators used are +, - or *, /

First, let us perform the swap using +, - operators,

let a = 5;
let b = 10;

//swap operations
a = a + b; //a = 15
b = a - b; //b = 5
a = a - b; //a = 10

//swap complete

console.log(a); //a is now 10
console.log(b); //b is now 5

Now, let us perform the swap using *, / operators,

let a = 7;
let b = 5;

//swap operations
a = a * b; //a = 35
b = a / b; //b = 7
a = a / b; //a = 5

//swap complete

console.log(a); //a is now 5
console.log(b); //b is now 7

Hope this was helpful😊

JavaScript number sorting using default sort method

Rakshith holla — Sun, 13 Dec 2020 03:37:53 +0000

JavaScript has a default sort function which can be used to sort a list of values.

usage -> array_name.sort();

However, this sort method returns incorrectly for numbers, since this considers all values as string and sorts the list of numbers by comparing with the ASCII value of the individual values.

This can be resolved by using comparison inside of the sort method.

ascending order sorting

array_name.sort(function(a, b){
  return a - b;
});

descending order or reverse sorting

array_name.sort(function(a, b){
  return b - a;
});