This JavaScript Cheatsheet is an essential resource for developers, providing a quick and easy reference to commonly used JavaScript methods or functions. It helps the development process by reducing the time spent searching for information, allowing developers to concentrate on writing code and solving problems. Whether you're a beginner or an experienced coder, this cheatsheet will enhance your productivity.

[Array] Method

• Built-in functions that allow you to perform various operations on arrays. These methods help you manipulate arrays, such as adding or removing elements, searching, sorting, and transforming the data stored in the arrays. Please below see commonly used array methods :

[1, 2, 3].length; // 3
[1, 2, 3].push(4); // [1, 2, 3, 4]
[1, 2, 3].unshift(0); // [0, 1, 2, 3]
[1, 2, 3].pop(3); // [1, 2]
[1, 2, 3].shift(); // [2,3]
[1, 2, 3].at(2); // 3
[1, 2, 3].indexOf(3); // 2
[1, 2, 3].includes(3); // true
[1, 2, 3].map((num)=> num)); // 1 2 3
[1, 2, 3].filter((num)=> num > 1)); // [2, 3]
[1, 2, 3].every((num)=> num > 0)); // true
[1, 2, 3].some((num)=> num > 2)); // true
[1, 2, 3].fill(0); // [0, 0, 0]
[1, 2, 3].reduce((acc , num)=> acc + num, 0); // 6
[1, 2, 3].concat([4, 5]); // [1, 2, 3, 4, 5]
[1, 2, 3].reverse(); // [3, 2, 1]
[3, 2, 1].sort(); // [1, 2, 3]
[1, 2, 3].join('-'); // "1-2-3"
[1, 2, 3].flat(); // [1, 2, 3]
[1, 2, 3].find((num)=> num === 1)); // 1
[1, 2, 3].findIndex((num)=> num === 2)); // 1
[1, 2, 3].toString(); // "1,2,3"
[1, 2, 3].toLocaleString(); // "1,2,3"
[1, 2, 3].slice(1, 2); // [2]
[1, 2, 3].splice(1, 1, "a"); // [1, 'a', 3]
Array.isArray([1,2,3]); // true
Array.from("123") // ['1', '2', '3']

"String" Method

• String methods are functions that perform specific operations on string values. Please see below commonly used string methods :

"JavaScript".length // 10
"JavaScript".[2] // 'v'
"JavaScript".charAt(2); // 'v'
"JavaScript".indexOf("S"); // 4
"JavaScript".toLowerCase(); // 'javascript'
"JavaScript".toUpperCase(); // 'JAVASCRIPT'
"JavaScript".slice(2, 5); // 'vaS'
"JavaScript".substring(2, 5); // 'vaS'
"JavaScript".substr(2,2); // 'va'
"JavaScript".concat(" Developer"); // 'JavaScript Developer'
"JavaScript Developer".split(" "); // ['JavaScript', 'Developer']
"JavaScript Developer".includes("Developer"); // true;
"Java Developer".replace("Developer", "JS"); // 'Java JS'
"Java Dev Dev".replaceAll("Dev", "JS"); // 'Java JS JS'
" JavaScript Developer ".trim(); // 'JavaScript Developer'
" JavaScript Developer ".trimStart(); // 'JavaScript Developer '
" JavaScript Developer ".trimEnd(); // ' JavaScript Developer'
"Dev".padStart(10, "*"); // '*******Dev'
"JavaScript".padEnd(10, "*"); // 'Dev*******'
"JavaScript Developer".startsWith("Java"); // true
"JavaScript Developer".endsWith("Developer"); // true
"JavaScript Dev".repeat(2); // 'JavaScript DevJavaScript Dev'
"JavaScript Dev".indexOf('JavaScript'); // 0
"JavaScript Dev".lastIndexOf("Dev"); // 11
"JavaScript Dev".search("Dev"); // 11
"JavaScript Dev".includes("Dev"); // true

To be continue....

Happy Coding! 🚀