Arrays & Lists
Work with collections of data using arrays and lists. Learn array methods like map, filter, reduce, iteration techniques, manipulation, sorting, and searching. Master data structures essential for organizing and processing information.
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What You'll Learn
Creating and accessing arrays
Array indexing and length
Iteration methods (forEach, for...of)
Transformation methods (map, filter, reduce)
Adding and removing elements
Sorting and searching arrays
Frequently Asked Questions
What is the difference between map, filter, and reduce?
map transforms each element and returns a new array of the same length. filter selects elements that meet a condition and returns a new array. reduce combines all elements into a single value (like a sum or object).
How do I add or remove elements from an array?
Use push() to add to the end, unshift() to add to the beginning, pop() to remove from the end, shift() to remove from the beginning, and splice() to add or remove elements at any position.
What is the best way to iterate over an array?
For simple iterations, use forEach() or for...of loops. For transformations, use map(). For filtering, use filter(). For aggregations, use reduce(). Choose the method that best expresses your intent.
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