https://github.com/hakeemsalman/javascript-practice-questions
Javascript Practice Questions
https://github.com/hakeemsalman/javascript-practice-questions
Last synced: 3 months ago
JSON representation
Javascript Practice Questions
- Host: GitHub
- URL: https://github.com/hakeemsalman/javascript-practice-questions
- Owner: hakeemsalman
- License: mit
- Created: 2024-10-29T08:03:56.000Z (7 months ago)
- Default Branch: main
- Last Pushed: 2024-11-05T08:57:17.000Z (7 months ago)
- Last Synced: 2025-03-10T04:15:16.723Z (3 months ago)
- Size: 2.93 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Javascript Practice Problems
> *Click ★ if you like the project. Your contributions are heartily ♡ welcome.*
**Table Contents**
- [Javascript Practice Problems](#javascript-practice-problems)
- [Find a prime number in an array](#find-a-prime-number-in-an-array)
- [Find an object in an array by one of its properties](#find-an-object-in-an-array-by-one-of-its-properties)
- [Find the index of a prime number in an array](#find-the-index-of-a-prime-number-in-an-array)
- [Sorting array of objects](#sorting-array-of-objects)
## Find a prime number in an array
```js
function isPrime(element, index, array) {
let start = 2;
while (start <= Math.sqrt(element)) {
if (element % start++ < 1) {
return false;
}
}
return element > 1;
}
console.log([4, 6, 8, 12].find(isPrime)); // undefined, not found
console.log([4, 5, 8, 12].find(isPrime)); // 5
```
## Find an object in an array by one of its properties
```js
const inventory = [
{ name: "apples", quantity: 2 },
{ name: "bananas", quantity: 0 },
{ name: "cherries", quantity: 5 },
];
function isCherries(fruit) {
return fruit.name === "cherries";
}
console.log(inventory.find(isCherries));
// { name: 'cherries', quantity: 5 }
```
## Find the index of a prime number in an array
```js
function isPrime(element) {
if (element % 2 === 0 || element < 2) {
return false;
}
for (let factor = 3; factor <= Math.sqrt(element); factor += 2) {
if (element % factor === 0) {
return false;
}
}
return true;
}
console.log([4, 6, 8, 9, 12].findIndex(isPrime)); // -1, not found
console.log([4, 6, 7, 9, 12].findIndex(isPrime)); // 2 (array[2] is 7)
```
## Sorting array of objects
```js
const items = [
{ name: "Edward", value: 21 },
{ name: "Sharpe", value: 37 },
{ name: "And", value: 45 },
{ name: "The", value: -12 },
{ name: "Magnetic", value: 13 },
{ name: "Zeros", value: 37 },
];
// sort by value
items.sort((a, b) => a.value - b.value);
// sort by name
items.sort((a, b) => {
const nameA = a.name.toUpperCase(); // ignore upper and lowercase
const nameB = b.name.toUpperCase(); // ignore upper and lowercase
if (nameA < nameB) {
return -1;
}
if (nameA > nameB) {
return 1;
}
// names must be equal
return 0;
});
```