This is just a list of little helpers I end up using in a lot of my applications. I'll try to add to it as time goes on. The following are listed alphabetically by function name.
A
/**
* arrayShuffle...drum roll please...shuffles an array
* The idea is to introduce some randomness into things
* The array is directly modified, not immutable
*
* This is the Fisher-Yates randomization method
* The idea is to count down from the back of the array
* As you go, you randomly pick a random one before it
*
*
* @param { array } array - array you want to shuffle
*/
export function arrayShuffle(array) {
for (let i = array.length - 1; i > 0; i--) {
const j = Math.floor(Math.random() * (i + 1));
// Basically we destructure the current and adjacent array indicies
// Then we swap them around, with j being a randomized index
[array[i], array[j]] = [array[j], array[i]];
}
}
D
/**
* dateFormatter()
*
* Desc: Takes an ISO 8601 date, and gives back an object:
*
* unixTime, a Unix integer timestamp (milliseconds since 1970-01-01, ie 1546300800000)
* month, full name of month (ie, "July")
* day, string with date and suffix (ie, "5th", "13th")
* year, 4 digit representation of the year (ie, "2021")
*
* Note: this uses setDateSuffix() listed below...
*
* @param { string } ISOdate - expects ISO 8601 date
*/
export const dateFormatter = (ISOdate) => {
// Parse date from ISO format
const newDate = new Date(ISOdate)
// Set up obj for results
// using a lot of date methods, check this out if you're rusty on dates:
// https://stackoverflow.com/questions/4321270/regarding-javascript-new-date-and-date-parse/66823255#66823255
return {
unixTime: Date.parse(newDate),
month: newDate.toLocaleString('en-us', { month: 'long' } ),
day: setDateSuffix(newDate.getDate()),
year: newDate.getFullYear()
}
}
R
/**
* randomID() - generates sufficiently random numbers for React key IDs
* @param { int } num - however random you want it
*/
export const randomID = (num) => {
return Math.round(Math.random() * num)
}
S
/**
* setDateSuffix()
*
* Desc: Takes two digit date, adds 'st', 'nd', 'rd', etc
*
* @param { integer } num - a number date
*/
export const setDateSuffix = (num) => {
const j = num % 10,
k = num % 100
if (j === 1 && k !== 11) {
return num + "st";
}
if (j === 2 && k !== 12) {
return num + "nd";
}
if (j === 3 && k !== 13) {
return num + "rd";
}
return num + "th";
}
T
// Type detection in JS
if(typeof(image) === 'string') {
// do work
}
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