Anagram Check - JavaScript Program

// Anagram: Same characters, different order // Examples: "listen" and "silent", "evil" and "vile" // Method 1: Sort and compare function isAnagram1(str1, str2) { // Normalize: lowercase, remove spaces str1 = str1.toLowerCase().replace(/\s/g, ''); str2 = str2.toLowerCase().replace(/\s/g, ''); // Sort and compare return str1.split('').sort().join('') === str2.split('').sort().join(''); } console.log("listen & silent:", isAnagram1("listen", "silent")); console.log("hello & world:", isAnagram1("hello", "world")); console.log("The Morse Code & Here come dots:", isAnagram1("The Morse Code", "Here come dots")); // Method 2: Character frequency count function isAnagram2(str1, str2) { str1 = str1.toLowerCase().replace(/\s/g, ''); str2 = str2.toLowerCase().replace(/\s/g, ''); if (str1.length !== str2.length) return false; let count1 = {}; let count2 = {}; // Count characters in str1 for (let char of str1) { count1[char] = (count1[char] || 0) + 1; } // Count characters in str2 for (let char of str2) { count2[char] = (count2[char] || 0) + 1; } // Compare counts for (let char in count1) { if (count1[char] !== count2[char]) { return false; } } return true; } console.log("\nUsing frequency:"); console.log("listen & silent:", isAnagram2("listen", "silent")); console.log("aabb & abab:", isAnagram2("aabb", "abab")); // Method 3: Single object count function isAnagram3(str1, str2) { str1 = str1.toLowerCase().replace(/\s/g, ''); str2 = str2.toLowerCase().replace(/\s/g, ''); if (str1.length !== str2.length) return false; let count = {}; // Increment for str1 for (let char of str1) { count[char] = (count[char] || 0) + 1; } // Decrement for str2 for (let char of str2) { if (!count[char]) return false; count[char]--; } return true; } console.log("\nSingle object:"); console.log("evil & vile:", isAnagram3("evil", "vile"));

This program demonstrates different methods to check if two strings are anagrams.

Anagram Definition

Two strings are anagrams if:

They contain same characters
Same frequency of each character
Different order

Examples:

"listen" ↔ "silent"
"evil" ↔ "vile"
"The Morse Code" ↔ "Here come dots"

Method 1: Sort and Compare

Sort both strings and compare:

javascript
str1.split('').sort().join('') === 
str2.split('').sort().join('');

Steps:

Convert to arrays
Sort both
Join back to strings
Compare

Time Complexity: O(n log n) due to sort

Method 2: Character Frequency

Count character occurrences:

javascript
let count1 = {};
for (let char of str1) {
    count1[char] = (count1[char] || 0) + 1;
}
// Compare counts

Object Counting:

count[char] || 0: Default to 0 if undefined
Increment count for each character

Method 3: Single Object

More efficient:

javascript
// Increment for str1
for (let char of str1) {
    count[char] = (count[char] || 0) + 1;
}

// Decrement for str2
for (let char of str2) {
    if (!count[char]) return false;
    count[char]--;
}

How it works:

Increment counts for str1
Decrement counts for str2
If all become 0, they're anagrams

Time Complexity:

Sort method: O(n log n)
Frequency methods: O(n) - Better!

Edge Cases:

Different lengths: Not anagrams
Case sensitivity: Normalize with toLowerCase()
Spaces: Remove with replace()

When to Use:

Sort: Simple, readable
Frequency: More efficient, handles duplicates well

Output