Merge branch 'master' of https://github.com/GrosSacASac/JavaScript-Set-Up

Author: Cyril Walle

js/Object.js

@@ -1,11 +1,81 @@
-/*Knowledge about Object*/
+/* Knowledge about Object */
 "use strict";
-/*How to create an empty Object ?*/
+
+/* How to create an empty Object ? */
 let anObject;
 
-// same 
+// same
 anObject = Object.create(Object);
+anObject = Object();
 anObject = {};
 
 // without prototype
-anObject = Object.create(null);
+anObject = Object.create(null);
+
+// creating with prefilled properties
+anObject = {
+    "key1": "value1",
+    "key2": "value2",
+};
+
+// assign simple
+anObject["key"] = "value";
+
+// assign multiple
+Object.assing(anObject, {
+    "key1": "value1",
+    "key2": "value2"
+});
+
+// get a specific value
+anObject["key"];
+
+// get Length
+Object.keys(anObject).length;
+Object.values(anObject).length;
+Object.entries(anObject).length;
+
+// iterate over
+// keys only
+Object.keys(anObject).forEach(function (key) {
+
+});
+
+// values only
+Object.values(anObject).forEach(function (value) {
+
+});
+
+// keys and values
+Object.entries(anObject).forEach(function ([key, value]) {
+
+});
+
+// has a key
+anObject.hasOwnProperty("key");
+
+// has safe, works even when anObject has a key "hasOwnProperty"
+Object.prototype.hasOwnProperty.call(anObject, "key");
+
+// remove a value
+anObject["key"] = undefined;
+
+// completly remove a property (key and value)
+delete anObject["key"];
+
+// prevent future extensions
+Object.preventExtensions(anObject);
+anObject["newThing"] = 2; // Error in strict mode
+
+// prevent future extensions and removals
+anObject["beforeSealing"] = 10;
+Object.seal(anObject);
+anObject["newThing"] = 2; // Error in strict mode
+delete anObject["beforeSealing"]; // Error in strict mode
+
+// prevent future extensions and removals and mutations
+anObject["beforeSealing"] = 10;
+Object.freeze(anObject);
+anObject["newThing"] = 2; // Error in strict mode
+delete anObject["beforeSealing"]; // Error in strict mode
+anObject["beforeSealing"] = 11; // Error in strict mode

js/Set.js

@@ -24,7 +24,6 @@ s.add(6);
 s.add(7);
 
 let l = listFromSet(s);
-let l2 =  listFromSet2(s);
-let l3 =  listFromSet3(s);
-
-console.log(s, l, l2, l3);
+let l2 = listFromSet2(s);
+let l3 = listFromSet3(s);
+let l4 = [...s];

js/tricks.md

@@ -3,12 +3,13 @@
 ## `Object.assign` is also useful on arrays
 
 ```
-const initialScores = [0, 0, 0];
-// player a, player b, total games
-const scores = [5, 2, 7];
+const initialScores = [0, 0];
+// player a, player b, total games played
+const state = [5, 2, 7];
 
-// reset scores
-Object.assign(scores, initialScores);
+// reset scores only
+Object.assign(state , initialScores);
+// state = [0, 0, 7];
 ```
 
 ## `{}` can be used to create local scopes anywhere