Exercise 10: Count Occurrences of Each Character
Problem Statement
Create a function `charCount(str)` that returns count of each character in string.
Example: charCount("hello") → {h: 1, e: 1, l: 2, o: 1}
Sample Output:
charCount("hello") => {h: 1, e: 1, l: 2, o: 1}
charCount("aabbcc") => {a: 2, b: 2, c: 2}Solution
const charCount = (str) => {
const count = {};
for (const char of String(str ?? "")) {
count[char] = (count[char] || 0) + 1;
}
return count;
};Explanation
Overall Goal:
- String me har character ki frequency count karna.
Line 1: Function header
const charCount = (str) => {
Line 2: Count object
const count = {};
Line 3: Iterate characters
for (const char of String(str ?? ""))
Line 4: Increment count
count[char] = (count[char] || 0) + 1;
Real world:
- Text analysis: character frequency.
- Compression: frequency analysis.