Do we need to use parseInt for the '*' operator in JavaScript?

I have an array where I am mapping it at some point to calculate the sum and percentages. However, when I tried implementing the logic, I noticed that using '*' directly works fine but using '+' adds the two strings together.

For example:

const a = '100';
const b = '10';

const c = a * b;

const d = a + b;

console.log(d)

When I checked the value of d, it returned '10010' while c gave '1000'. This confusion led me to wonder why this is happening.

But then, trying parseInt(a) + parseInt(b) worked perfectly with output as 110.

javascript

Answer №1

When it comes to JavaScript, primitive datatypes such as int and float do not exist. Instead, variables can be initialized with any type of data. Take for example:

const a = 100;
const b = 10;

const c = a * b;

const d = a + b;

console.log(d);

This code should function correctly without the need for quotes around the numbers. By excluding the quotes, we ensure that the constants are storing numeric values rather than strings. In your original example, using the plus operator (+) would result in concatenation rather than addition because the constants were being treated as strings due to the presence of quotes.

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