Frequency Map

Data Structures, Operators & Stringsmedium

Course · Section 9: Data Structures, Modern Operators and Strings · Lecture 118: Enhanced Object Literals

Implement `frequency(arr)` returning an object mapping each value to how many times it appears.

Input: frequency(["a","b","a","c","a"])

Output: {"a":3,"b":1,"c":1}

Input: frequency([])

Output: {}

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Common pitfalls

Approach & explanation (try first)

Tallying each value into an object builds a frequency map in one pass.

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