DEV Community: yns

How to check if a value is present in an array.

yns — Wed, 30 Apr 2025 13:41:19 +0000

When working with arrays in JavaScript, one of the cleanest and most efficient ways to check if a value exists is by using the some() method.

✅ What is `some()`?

some() is an array method that takes a callback function.
It returns:
- true if at least one element satisfies the condition.
- false if no elements match.
It stops iterating as soon as a match is found (great for performance).

Example:

const arr = ['a', 'b', 'c'];
const check = arr.some(x => x === 'z');
// Output: false

What is The Ternary Operator In JavaScript ?

yns — Wed, 14 Aug 2024 14:51:06 +0000

Here is The syntax:

So basically , It is another way to write the conditional statements (if / else / else if ) in a much simpler way. It is especially used for the non-complex cases.
for example , instead of this:

let a = 4;
if (a > 4)
{
console.log("ok");
}
else
{
console.log("not ok");
}

We can just do this:

a > 4 ? console.log("ok") : console.log("not ok");

Difference Between Number() and parseInt() in Converting Strings?

yns — Sun, 23 Jun 2024 09:10:17 +0000

Number(): Searches the entire string for numbers. If it finds anything else, it will return NaN (short for Not a Number).

parseInt() / parseFloat(): Returns the first number in the string, ignoring the rest. If there are no numbers at the beginning of the string, it will return NaN.

let's take an example:

Example 1:
let a = "1hola1"; console.log(Number(a)); console.log(parseInt(a)); output-> NaN 1

Example 2:
let a = "1"; console.log(Number(a)); console.log(parseInt(a)); output-> 1 1

In conclusion , We use Number() for the Strings that only contains numbers,the parseInt() does the opposite.

Difference Between ++a And a++ In JavaScript?

yns — Sat, 22 Jun 2024 14:15:47 +0000

The ++ is responsible of the increment of the number value by 1 . But have you wondered what is the difference between putting it before or after?

++a : returns the value after the increment.
a++ : returns the value before the increment.

Let's take an example:

let a=0; a++; ++a;
the output will be:
output->0 1

.

yns — Fri, 24 May 2024 10:51:38 +0000