feat(chapter_hashing): Add js and ts codes for chapter hashing (#675)

* refactor(chapter_hashing): Remove unnecessary chaining operator

* feat(chapter_hashing): Add js and ts codes for chapter 6

* refactor(chapter_hashing): Optimize the remove function logic

* refactor(chapter_hashing): Remove unnecessary chaining operator

* refactor(chapter_hashing): use const instead of let

codes/javascript/chapter_hashing/simple_hash.js

@@ -0,0 +1,60 @@
+/**
+ * File: simple_hash.js
+ * Created Time: 2023-08-06
+ * Author: yuan0221 (yl1452491917@gmail.com)
+ */
+
+/* 加法哈希 */
+function addHash(key) {
+    let hash = 0;
+    const MODULUS = 1000000007;
+    for (const c of key) {
+        hash = (hash + c.charCodeAt(0)) % MODULUS;
+    }
+    return hash;
+}
+
+/* 乘法哈希 */
+function mulHash(key) {
+    let hash = 0;
+    const MODULUS = 1000000007;
+    for (const c of key) {
+        hash = (31 * hash + c.charCodeAt(0)) % MODULUS;
+    }
+    return hash;
+}
+
+/* 异或哈希 */
+function xorHash(key) {
+    let hash = 0;
+    const MODULUS = 1000000007;
+    for (const c of key) {
+        hash ^= c.charCodeAt(0);
+    }
+    return hash & MODULUS;
+}
+
+/* 旋转哈希 */
+function rotHash(key) {
+    let hash = 0;
+    const MODULUS = 1000000007;
+    for (const c of key) {
+        hash = ((hash << 4) ^ (hash >> 28) ^ c.charCodeAt(0)) % MODULUS;
+    }
+    return hash;
+}
+
+/* Driver Code */
+const key = 'Hello 算法';
+
+let hash = addHash(key);
+console.log('加法哈希值为 ' + hash);
+
+hash = mulHash(key);
+console.log('乘法哈希值为 ' + hash);
+
+hash = xorHash(key);
+console.log('异或哈希值为 ' + hash);
+
+hash = rotHash(key);
+console.log('旋转哈希值为 ' + hash);