Hi there, my name is Rahul and I am 18 years old. My goal is to become a successful developer, and I am interested in building web apps with frontend technologies.
Today, I'd like to share some useful JavaScript stuff I have saved and I think it can help make your life as a developer easier.
Let's get started!
- Generate a random number between two values:
const randomNumber = Math.random() * (max - min) + min - Check if a number is an integer:
const isInteger = (num) => num % 1 === 0 - Check if a value is
nullorundefined:const isNil = (value) => value === null || value === undefined - Check if a value is a truthy value:
const isTruthy = (value) => !!value - Check if a value is a falsy value:
const isFalsy = (value) => !value - Check if a value is a valid credit card number:
const isCreditCard = (cc) => {
const regex = /^(?:4[0-9]{12}(?:[0-9]{3})?|[25][1-7][0-9]{14}|6(?:011|5[0-9][0-9])[0-9]{12}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|(?:2131|1800|35\d{3})\d{11})$/;
return regex.test(cc);
}
- Check if a value is an object:
const isObject = (obj) => obj === Object(obj) - Check if a value is a function:
const isFunction = (fn) => typeof fn === 'function' - Remove Duplicated from Array
const removeDuplicates = (arr) => [...new Set(arr)]; - Check if a value is a promise:
const isPromise = (promise) => promise instanceof Promise - Check if a value is a valid email address:
const isEmail = (email) => {
const regex = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
return regex.test(email);
}
- Check if a string ends with a given suffix:
const endsWith = (str, suffix) => str.endsWith(suffix) - Check if a string starts with a given prefix:
const startsWith = (str, prefix) => str.startsWith(prefix) - Check if a value is a valid URL:
const isURL = (url) => {
const regex = /^(?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~:/?#[\]@!\$&'\(\)\*\+,;=.]+$/;
return regex.test(url);
}
- Check if a value is a valid hexadecimal color code:
const isHexColor = (hex) => {
const regex = /^#?([0-9A-Fa-f]{6}|[0-9A-Fa-f]{3})$/;
return regex.test(hex);
}
- Check if a value is a valid postal code:
const isPostalCode = (postalCode, countryCode) => {
if (countryCode === 'US') {
const regex = /^[0-9]{5}(?:-[0-9]{4})?$/;
return regex.test(postalCode);
} else if (countryCode === 'CA') {
const regex = /^[ABCEGHJKLMNPRSTVXY][0-9][ABCEGHJKLMNPRSTVWXYZ] [0-9][ABCEGHJKLMNPRSTVWXYZ][0-9]$/;
return regex.test(postalCode.toUpperCase());
} else {
// Add regex for other country codes as needed
return false;
}
}
- Check if a value is a DOM element:
const isDOMElement = (value) => typeof value === 'object' && value.nodeType === 1 && typeof value.style === 'object' && typeof value.ownerDocument === 'object';
- Check if a value is a valid CSS length (e.g.
10px,1em,50%):
const isCSSLength = (value) => /^([-+]?[\d.]+)(%|[a-z]{1,2})$/.test(String(value));
- Check if a value is a valid date string (e.g.
2022-09-01,September 1, 2022,9/1/2022):
const isDateString = (value) => !isNaN(Date.parse(value));
- Check if a value is a number representing a safe integer (those integers that can be accurately represented in JavaScript):
const isSafeInteger = (num) => Number.isSafeInteger(num) - Check if a value is a valid Crypto address:
//Ethereum
const isEthereumAddress = (address) => {
const regex = /^0x[a-fA-F0-9]{40}$/;
return regex.test(address);
}
//bitcoin
const isBitcoinAddress = (address) => {
const regex = /^[13][a-km-zA-HJ-NP-Z0-9]{25,34}$/;
return regex.test(address);
}
// ripple
const isRippleAddress = (address) => {
const regex = /^r[0-9a-zA-Z]{33}$/;
return regex.test(address);
}
- Check if a value is a valid RGB color code
const isRGBColor = (rgb) => {
const regex = /^rgb\(\s*\b([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\b\s*,\s*\b([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\b\s*,\s*\b([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\b\s*\)$/;
return regex.test(rgb);
}
- Quickly create an array of characters from a string:
const string = "abcdefg";
const array = [...string];
- Quickly create an object with all the properties and values of another object, but with a different key for each property
const original = {a: 1, b: 2, c: 3};
const mapped = {...original, ...Object.keys(original).reduce((obj, key) => ({...obj, [key.toUpperCase()]: original[key]}), {})};
- Quickly create an array of numbers from 1 to 10
const array = [...Array(10).keys()].map(i => i + 1);
- Quickly shuffle an array
const shuffle = (array) => array.sort(() => Math.random() - 0.5);
- Convert an array-like object (such as a NodeList) to an array
const toArray = (arrayLike) => Array.prototype.slice.call(arrayLike);
- Sort Arrays
//Ascending
const sortAscending = (array) => array.sort((a, b) => a - b);
//Descending
const sortDescending = (array) => array.sort((a, b) => b - a);
- Debounce a function
const debounce = (fn, time) => {
let timeout;
return function(...args) {
clearTimeout(timeout);
timeout = setTimeout(() => fn.apply(this, args), time);
};
};
- Open a new tab with a given URL
const openTab = (url) => {
window.open(url, "_blank");
};
- Get the difference between two dates
const dateDiff = (date1, date2) => Math.abs(new Date(date1) - new Date(date2));
- Generate a random string of a given length
const randomString = (length) => {
let result = "";
const characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
for (let i = 0; i < length; i++) {
result += characters.charAt(Math.floor(Math.random() * characters.length));
}
return result;
};
- Get value of cookie
const getCookie = (name) => {
const value = `; ${document.cookie}`;
const parts = value.split(`; ${name}=`);
if (parts.length === 2) return parts.pop().split(";").shift();
};
Thank you for Reading. It is important to note that simply copying and pasting code without understanding how it works can lead to problems down the line. It is always a good idea to test the code and ensure that it functions properly in the context of your project.
Additionally, don't be afraid to customize the code to fit your specific needs. As a helpful tip, consider saving a collection of useful code snippets for quick reference in the future.
I am also learning, if I am going wrong somewhere let me know.
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