simple hash table

Author: amejiarosario

src/07-object-oriented-design/hash-table.js

@@ -0,0 +1,20 @@
+class HashTable {
+  constructor(size = 100) {
+    this.size = +size;
+    this.table = new Array(size);
+  }
+
+  set(key, value) {
+    this.table[this.hash(key)] = value;
+  }
+
+  get(key) {
+    return this.table[this.hash(key)];
+  }
+
+  hash(key, max) {
+    return JSON.stringify(key).split('').reduce((sum, letter) => sum += letter.charCodeAt(), 0) % this.size;
+  }
+}
+
+module.exports = HashTable;

src/07-object-oriented-design/hash-table.spec.js

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+const expect = require('chai').expect;
+const HashTable = require('./hash-table');
+
+describe('HashTable', function() {
+  it('should set and element and get it', function () {
+    const hash = new HashTable();
+    hash.set('adrian', 100);
+    expect(hash.get('adrian')).to.equal(100);
+  });
+
+  it('should set an array as key and get it', function () {
+    const hash = new HashTable();
+    hash.set([10, 293], 'bomb');
+    expect(hash.get([10,   293])).to.equal('bomb');
+  });
+
+  it('should take size as parameter', function () {
+    const hash = new HashTable(1);
+    hash.set(1, 'test');
+    expect(hash.get(1)).to.equal('test');
+  });
+
+  it('should avoid collisions', function () {
+    const hash = new HashTable(1);
+    hash.set('en', 'test');
+    hash.set('sp', 'prueba');
+    expect(hash.get('en')).to.equal('test');
+    expect(hash.get('sp')).to.equal('prueba');
+  });
+});