Here are 20 useful JavaScript snippets that can help you when working on your projects:
1. Get current date and time:
const now = new Date();
2. Check if a variable is an array:
Array.isArray(variable);
3. Merge two arrays:
const newArray = array1.concat(array2);
4. Remove duplicates from an array:
const uniqueArray = [...new Set(array)];
5. Sort an array in ascending order:
array.sort((a, b) => a - b);
6. Reverse an array:
array.reverse();
7. Convert string to number:
const number = parseInt(string);
8. Generate a random number between two values:
const randomNumber = Math.floor(Math.random() * (max - min + 1)) + min;
9. Check if a string contains a substring:
string.includes(substring);
10. Get the length of an object:
Object.keys(object).length;
11. Convert object to array:
const array = Object.entries(object);
12. Check if an object is empty:
((typeof object)=="object") && Object.keys(object).length==0;
13. Get current URL:
const currentUrl = window.location.href;
14. Redirect to a new URL:
window.location.replace(url);
15. Set a cookie:
document.cookie = "name=value; expires=date; path=path; domain=domain; secure";
16. Get a cookie:
const cookieValue = document.cookie.replace(/(?:(?:^|.*;\s*)name\s*\=\s*([^;]*).*$)|^.*$/, "$1");
17. Check if a cookie exists:
document.cookie.split(';').some((item) => item.trim().startsWith('name='))
18. Remove a cookie:
document.cookie = "name=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=path; domain=domain; secure";
19. Get the current viewport dimensions:
const viewportWidth = Math.max(document.documentElement.clientWidth || 0, window.innerWidth || 0); const viewportHeight = Math.max(document.documentElement.clientHeight || 0, window.innerHeight || 0);
20. Copy text to clipboard:
navigator.clipboard.writeText(text);
These JavaScript snippets can help save time and simplify your code when working on web projects.
12 is wrong.
Correct way:
Test the type before checked the length.
Checked the length, can do an unpredictable result.
For example, checking the length of a numeric is nonsense.