JavaScript array methods I often use in building production apps

JavaScript offers a range of methods to work with and manipulate arrays. These methods make our tasks easier and our code cleaner and more robust. Let's take a look at some of these methods that I frequently use, and probably, you'll also use them in building production applications.

The ‘find’ method

• The find method returns the first element in an array that satisfies the specified conditions.
• It takes a callback function as an argument containing the conditions, where the callback function must return a boolean.
• It executes the conditions in the callback function for each element in an array without modifying the array.
• The primary use case of the find method is to get an array element that matches specific conditions.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const cheese = ingredients.find((ingredient) => ingredient === 'cheese');

console.log(cheese); // cheese

The ‘filter’ method

• The filter method returns an array containing all elements that satisfy the specified conditions.
• It takes a callback function as an argument containing the conditions, where the callback function must return a boolean.
• It executes the conditions in the callback function for each element in an array without modifying the array.
• The primary use case of the filter method is to get an array of elements that match specific conditions.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const filtered = ingredients.filter((ingredient) => ingredient === 'cheese');

console.log(filtered); // [ 'cheese' ]

The ‘every’ method

• The every method returns a boolean by checking whether all elements in an array meet the specified conditions.
• It takes a callback function as an argument containing the conditions, where the callback function must return a boolean.
• It executes the conditions in the callback function for each element in an array without modifying the array.
• The primary use case of the every method is to check if all elements in an array match specific conditions.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const isRequiredLength = ingredients.every(
  (ingredient) => ingredient.length > 3
);

console.log(isRequiredLength); // true

The ‘some’ method

• The some method returns a boolean by checking if at least one element in an array meets the specified conditions.
• It takes a callback function as an argument containing the conditions, where the callback function must return a boolean.
• It executes the conditions in the callback function for each element in an array without modifying the array.
• The primary use case of the some method is to check if at least one element in an array matches specific conditions.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const hasLongWord = ingredients.some((ingredient) => ingredient.length > 6);

console.log(hasLongWord); // true

The ‘map’ method

• The map method returns an array by modifying the elements.
• It takes a callback function containing the modification logic.
• It executes the modification logic in the callback function for each element in an array without modifying the array.
• The primary use case of the map method is to modify array elements and get a new array with the modified elements.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const updated = ingredients.map((ingredient) => `I love ${ingredient}`);

console.log(updated); // [ 'I love cheese', 'I love chicken', 'I love garlic', 'I love mayo' ]

The ‘includes’ method

• The include method returns a boolean by checking if a specific element exists in an array.
• It takes an argument and checks if it exists in an array without modifying the array.
• The primary use case of the includes method is to check if a particular element exists in an array.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const hasCheese = ingredients.includes('cheese');

console.log(hasCheese); // true

The ‘join’ method

• The join method returns a string by joining the elements in an array using a specified separator.
• It takes an argument and uses it to join each element with the other in an array without modifying the array.
• The primary use case of the join method is to transform an array into a string.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const ingredientsStr = ingredients.join(', ');

console.log(ingredientsStr); // cheese, chicken, garlic, mayo

The ‘push’ method

• The push method adds one or more elements to the end of an array and returns the updated array's length.
• It takes one or more arguments, which are the elements to be added to an array.
• It modifies an array by adding the arguments to the end of the array.
• The primary use case of the push method is to add elements at the end of an array.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const updatedLength = ingredients.push('beef');

console.log(updatedLength); // 5

The ‘slice’ method

• The slice method returns a shallow copy of an array.
• It usually takes two arguments, the start and end indexes, and uses them to copy a portion of an array where the end index is not included.
• It operates without modifying the original array.
• The primary use case of the slice method is to create a copy of a portion of an array.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const sliced = ingredients.slice(1, 2);

console.log(sliced); // [ 'chicken' ]

The ‘sort’ method

• The sort method returns an array by sorting the elements.
• It can optionally take a callback function containing the sort conditions.
• It modifies an array by executing the sort conditions in the callback function for each element in the array.
• The primary use case of the sort method is to sort the elements in an array.

const ingredients = ['cheese', 'chicken', 'garlic', 'mayo'];

const sorted = ingredients.sort((a, b) => a.length - b.length);

console.log(sorted); // [ 'mayo', 'cheese', 'garlic', 'chicken' ]

These are some of the array methods I frequently use when building JavaScript applications. I hope you now have a clear understanding of these methods and how, why, and where to utilize them.

I have an article on JavaScript string methods I frequently use in building production apps, which you might find interesting. Feel free to take a look. Happy learning!