Improving the documentation - How hash table works

Author: miladsade96

Data-Structures/HashTable/HashTable.js

@@ -1,67 +1,95 @@
 export default class HashTable {
   constructor(limit = 100) {
+    // Initialize the storage and limit variables
     this.storage = new Array(limit)
     this.limit = limit
   }
 
+  // Hash function:
   _hash(key, max) {
+    // Initialize the hash variable to 0
     let hash = 0
+    // Iterate through the key and add the character code at each iteration to the hash variable
     for (let i = 0; i < key.length; i++) hash += key.charCodeAt(i)
+    // Return the hash modulo the max
     return hash % max
   }
 
+  // Insert a key-value pair into the hash table
   set(key, value) {
+    // Hash the key
     const index = this._hash(key, this.limit)
+    // If the index is empty, insert the key-value pair and create a bucket
     if (this.storage[index] === undefined) this.storage[index] = [[key, value]]
     else {
+      //  If the index is not empty, iterate through the bucket (collision handling)
       let inserted = false
       for (let i = 0; i < this.storage[index].length; i++) {
         if (this.storage[index][i][0] === key) {
+          // If the key exists, update the value
           this.storage[index][i][1] = value
           inserted = true
         }
       }
+      // If the key does not exist, insert the key-value pair
       if (inserted === false) this.storage[index].push([key, value])
     }
   }
 
   // Get a value from the hash table
   get(key) {
+    // Hash the key
     const index = this._hash(key, this.limit)
+    // If the index is empty, return undefined
     if (this.storage[index] === undefined) return undefined
     else {
+      // If the index is not empty, iterate through the bucket
       for (let i = 0; i < this.storage[index].length; i++) {
+        // If the key exists, return the value
         if (this.storage[index][i][0] === key) return this.storage[index][i][1]
       }
     }
   }
 
+  // Remove a key-value pair from the hash table
   remove(key) {
+    // Hash the key
     const index = this._hash(key, this.limit)
+    // Check if the bucket exists
     if (this.storage[index]) {
+      // If the key matches the key at the index and there is only one item in the bucket, delete the bucket
       if (
         this.storage[index].length === 1 &&
         this.storage[index][0][0] === key
       ) {
         delete this.storage[index]
       } else {
+        // If the index is not empty, iterate through the bucket
         for (let i = 0; i < this.storage[index].length; i++) {
+          // If the key exists, delete the key-value pair
           if (this.storage[index][i][0] === key) delete this.storage[index][i]
         }
       }
     }
   }
 
+  // Check if a key exists in the hash table
   has(key) {
+    // Hash the key to find the index
     const index = this._hash(key, this.limit)
+    // Check if the bucket at the index exists
     if (this.storage[index]) {
+      // Iterate through the bucket's key-value pairs
       for (let i = 0; i < this.storage[index].length; i++) {
+        // Compare the current key with the target key and if the key is found, return true
         if (this.storage[index][i][0] === key) return true
       }
     }
+    // If the key is not found, return false
     return false
   }
 
+  // Print all keys/values in the table
   printTable() {
     for (let i = 0; i < this.storage.length; i++) {
       if (this.storage[i] !== undefined)
@@ -70,6 +98,7 @@ export default class HashTable {
     }
   }
 
+  // Clear all key/values
   clear() {
     this.storage = new Array(this.limit)
   }