Javascript snippets you need to know right now!
10 JS snippets of code every week to empower you to write better.
Abhiraj Bhowmick
JavaScript is one of the most popular languages you can learn. As many people say: “If you’re going to learn just one programming language, go for JavaScript.”
If this sounds compelling to you, I am starting a series where I give 10 Javascript snippets every Wednesday for 5 weeks.
This tweet of mine had originally inspired me to create this series, do drop a like, and follow me.

Here’s a list of 10 beneficial snippets that you can learn and use immediately.
Let's get started!
1️⃣ all
This snippet returns true if the predicate function returns true for all elements in a collection and false otherwise. You can omit the second argument 'fn' if you want to use Boolean as a default value.
all([4, 2, 3], x => x > 1); // true
all([1, 2, 3]); // true
2️⃣ arrayToCSV
This snippet converts the elements to strings with comma-separated values.
arr.map(v => v.map(x => `"${x}"`).join(delimiter)).join('\n');
arrayToCSV([['a', 'b'], ['c', 'd']]); // '"a","b"\n"c","d"'
arrayToCSV([['a', 'b'], ['c', 'd']], ';'); // '"a";"b"\n"c";"d"'
3️⃣ arrayToHtmlList
This snippet converts the elements of an array into list tags and appends them to the list of the given ID.
(el => (
(el = document.querySelector('#' + listID)),
(el.innerHTML += arr.map(item => `<li>${item}</li>`).join(''))
))();
arrayToHtmlList(['item 1', 'item 2'], 'myListID');
5️⃣ bifurcate
This snippet splits values into two groups and then puts a truthy element of filter in the first group, and in the second group otherwise.
You can use Array.prototype.reduce()and Array.prototype.push()to add elements to groups based on filter.
arr.reduce((acc, val, i) => (acc[filter[i] ? 0 : 1].push(val), acc), [[], []]);
bifurcate(['beep', 'boop', 'foo', 'bar'], [true, true, false, true]);
// [ ['beep', 'boop', 'bar'], ['foo'] ]
6️⃣ byteSize
This snippet returns the length of a string in bytes.
byteSize('😀'); // 4
byteSize('Hello World'); // 11
7️⃣ capitalize
This snippet capitalizes the first letter of a string.
first.toUpperCase() + rest.join('');
capitalize('fooBar'); // 'FooBar'
capitalize('fooBar', true); // 'Foobar'
8️⃣ dayOfYear
This snippet gets the day of the year from a Dateobject.
Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);
dayOfYear(new Date()); // 272
9️⃣ decapitalize
This snippet turns the first letter of a string into lowercase.
first.toLowerCase() + rest.join('')
decapitalize('FooBar'); // 'fooBar'
decapitalize('FooBar'); // 'fooBar'
🔟 countOccurrences
This snippet counts the occurrences of a value in an array.
countOccurrences([1, 1, 2, 1, 2, 3], 1); // 3
Until next Wed,
Abhiraj
Upvote
Abhiraj Bhowmick
I make stuff on the web and write blogs about it.

Related Articles