Jest added

Author: codeztech-atique

.gitignore

@@ -0,0 +1 @@
+./node_modules

Javascript/AdvancedLevel/generatorsAndObserver.js

@@ -0,0 +1,65 @@
+// Example - https://www.dofactory.com/javascript/design-patterns/observer#:~:text=The%20Observer%20pattern%20offers%20a,design%20and%20promotes%20loose%20coupling
+// Generators - They don't compute values all at the same time
+
+// Using Normal function -- You don't have enoug memory to allocated all the memory's
+// function range(upperbound) {
+//     const result = [];
+//     for(let i = 0; i < upperbound; i++) {
+//         result.push(i);
+//     }
+//     return result;
+// }
+
+// console.log(range(1000000000))
+
+
+// Using generator using In memory using i
+// next() also the part of generators 
+// function* range(upperbound) {
+//     for(let i = 0; i < upperbound; i++) {
+//        yield i;
+//     }
+// }
+
+// for(const e1 of range(1000000000)) {
+//     console.log(e1);
+// }
+
+
+// Observer using next
+// function* gen() {
+//     console.log('Started');
+//     try {
+//        let str = `1.  ${yield}`;
+//        console.log(str);
+//     } catch(e) {
+//        console.log('Caught Error');
+//     }
+//     console.log(`1. ${yield}`); // yield told me to pause or suspand
+//     console.log(`2. ${yield}`); // yield told me to pause or suspand
+//     console.log(`3. ${yield}`); // yield told me to pause or suspand
+//     return 'result';
+// }
+
+// const genObj = gen();
+
+// Normal way without error
+// genObj.next();
+// genObj.next('Atique');
+// genObj.next('sunny');
+// genObj.next('atique');
+// genObj.next('sonu');
+// genObj.next('sonu111');
+
+
+// Caught Error --
+
+// console.log(genObj.next());
+// console.log(genObj.throw(new Error('error')));
+
+
+// console.log(genObj.next('sunny1'))
+// console.log(genObj.next('sunny2'))
+// console.log(genObj.next('sunny3'))
+// console.log(genObj.next('sunny4'))
+// console.log(genObj.return('sunny4'))

Javascript/AdvancedLevel/index.js

@@ -0,0 +1,25 @@
+const obj = {};
+
+const memorizeFunction = (key) => {
+    if(obj[key]) {
+        console.log('Return from Cache', obj[key]);
+        return obj[key];
+    } else {
+        let value = key.split('-');
+        obj[key] = parseInt(value[0]) + parseInt(value[1]);
+        return obj[key];
+    }
+}
+
+const sum = (a, b) => {
+    let keyPair = a+"-"+b;
+    let result = memorizeFunction(keyPair);
+    return result;
+}
+
+
+
+console.log("Sum:", sum(5, 6));
+console.log("Sum:", sum(5, 6));
+console.log("Sum:", sum(6, 6));
+

Javascript/AdvancedLevel/map.js

@@ -0,0 +1,62 @@
+// Javascript Map
+const chalk = require('chalk');
+
+const map = new Map();
+
+map.set('foo', 123);
+// console.log(chalk.gray("Map values:"), map.get('foo'));
+
+// console.log(chalk.green("Map has:"), map.has('foo')); // True
+
+// console.log(chalk.red("Map Delete:"), map.delete('foo')); // True
+
+// console.log(chalk.blue("Map has:"), map.has('foo')); // False
+
+// Javascipt Map vs Object 
+
+// Object Concept --
+
+// let obj = {};
+
+// adding properties to a object
+// obj.prop1 = 1;
+// obj[2]    =  2;
+
+// getting nr of properties of the object
+// console.log(Object.keys(obj).length)
+
+// deleting a property
+// delete obj[2]
+
+// console.log(obj)
+
+// Map Concept --
+
+const myMap = new Map();
+
+const keyString = 'a string',
+    keyObj = {},
+    keyFunc = function() {};
+
+// setting the values
+myMap.set(keyString, "value associated with 'a string'");
+myMap.set(keyObj, 'value associated with keyObj');
+myMap.set(keyFunc, 'value associated with keyFunc');
+
+// console.log(myMap.size); // 3
+
+// getting the values
+console.log("--->", myMap.get(keyString));    // "value associated with 'a string'"
+console.log(myMap.get(keyObj));       // "value associated with keyObj"
+console.log(myMap.get(keyFunc));      // "value associated with keyFunc"
+
+console.log(myMap.get('a string'));   // "value associated with 'a string'"
+                         // because keyString === 'a string'
+console.log(myMap.get({}));           // undefined, because keyObj !== {}
+console.log(myMap.get(function() {})) // undefined, because keyFunc !== function () {}
+
+
+
+// Main diffrence Accidental Keys --- Like in the Object -- 
+// If we do obj['foo'] = '123'
+// Again obj['foo'] = '1234' // this will replace the previous record

Javascript/AdvancedLevel/proxy.js

@@ -0,0 +1,17 @@
+// Using Number
+
+// const abc = 11;
+// let abcHandler;
+
+// const proxyNumber = new Proxy(abc, abcHandler);
+// console.log(proxyNumber);
+
+// Using object
+// const target = {
+//     name: 'Atique'
+// }
+
+// const handler = {};
+// const proxy = new Proxy(target, handler);
+
+// console.log(proxy.name)

Javascript/AdvancedLevel/set.js

@@ -0,0 +1,23 @@
+// Javascipt Set
+
+// In ES5 Array lot of things are not possible which solved the Set concept, has been introduce in set
+// You can store Arbitary Value inside set
+
+// const arr = [NaN];
+
+// console.log(arr.indexOf('NaN'))
+
+
+// const set = new Set();
+
+// set.add('red');
+// set.add('blue');
+// set.add('yellow');
+// set.add('yellow');
+
+// console.log(set.has('red'));
+// console.log(set);
+
+// const setEntries = new Set(['apple', 'bowl', 'cat']);
+// const mapEntries = new Map(setEntries.entries());
+// console.log(mapEntries)