Anagram Check in JavaScript

1// Anagram: Same characters, different order
2// Examples: "listen" and "silent", "evil" and "vile"
3
4// Method 1: Sort and compare
5function isAnagram1(str1, str2) {
6    // Normalize: lowercase, remove spaces
7    str1 = str1.toLowerCase().replace(/\s/g, '');
8    str2 = str2.toLowerCase().replace(/\s/g, '');
9    
10    // Sort and compare
11    return str1.split('').sort().join('') === 
12           str2.split('').sort().join('');
13}
14
15console.log("listen & silent:", isAnagram1("listen", "silent"));
16console.log("hello & world:", isAnagram1("hello", "world"));
17console.log("The Morse Code & Here come dots:", 
18    isAnagram1("The Morse Code", "Here come dots"));
19
20// Method 2: Character frequency count
21function isAnagram2(str1, str2) {
22    str1 = str1.toLowerCase().replace(/\s/g, '');
23    str2 = str2.toLowerCase().replace(/\s/g, '');
24    
25    if (str1.length !== str2.length) return false;
26    
27    let count1 = {};
28    let count2 = {};
29    
30    // Count characters in str1
31    for (let char of str1) {
32        count1[char] = (count1[char] || 0) + 1;
33    }
34    
35    // Count characters in str2
36    for (let char of str2) {
37        count2[char] = (count2[char] || 0) + 1;
38    }
39    
40    // Compare counts
41    for (let char in count1) {
42        if (count1[char] !== count2[char]) {
43            return false;
44        }
45    }
46    
47    return true;
48}
49
50console.log("\nUsing frequency:");
51console.log("listen & silent:", isAnagram2("listen", "silent"));
52console.log("aabb & abab:", isAnagram2("aabb", "abab"));
53
54// Method 3: Single object count
55function isAnagram3(str1, str2) {
56    str1 = str1.toLowerCase().replace(/\s/g, '');
57    str2 = str2.toLowerCase().replace(/\s/g, '');
58    
59    if (str1.length !== str2.length) return false;
60    
61    let count = {};
62    
63    // Increment for str1
64    for (let char of str1) {
65        count[char] = (count[char] || 0) + 1;
66    }
67    
68    // Decrement for str2
69    for (let char of str2) {
70        if (!count[char]) return false;
71        count[char]--;
72    }
73    
74    return true;
75}
76
77console.log("\nSingle object:");
78console.log("evil & vile:", isAnagram3("evil", "vile"));