add code examples for chapter 4

Author: HansUXdev

JS/04-Objects/Functions/IIFE.js

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+/**
+ * Resources:
+ * 1. https://flaviocopes.com/javascript-iife/
+ * 2. https://stackabuse.com/javascripts-immediately-invoked-function-expressions/
+ * 3. https://medium.com/@vvkchandra/essential-javascript-mastering-immediately-invoked-function-expressions-67791338ddc6
+ */
+
+
+
+(   // open IIFE
+    // Inner Anonymous Function
+    function () { 
+        var tmp = "something";
+        console.log(tmp);
+        return tmp;
+    }
+()  // p
+);  // close IIFE
+
+
+/**
+ ** Passing Data
+ */
+(   // open IIFE
+
+    // Inner Anonymous Function
+    function (data) { 
+    
+        var tmp = data;  // not a global variable
+        console.log(tmp);
+    }
+("something else")
+);  // close IIFE
+
+// Arrow function
+(() => {
+    /* */
+  })()
+
+
+/**
+ * with unary operators
+ */
+
++function () {
+    // Code that runs in your function
+    console.log("+");
+}();
+
+-function () {
+    // Code that runs in your function
+    console.log("-");
+}();
+
+!function () {
+    console.log("!");
+    // Code that runs in your function
+}();
+
+~function () {
+    // Code that runs in your function
+    console.log("~");
+}();
+
+void function () {
+    // Code that runs in your function
+    console.log("void");
+}();
+
+
+
+for (var i = 1; i <= 5; i++) {
+    (function (step) {
+        setTimeout(
+            () => console.log(`I reached step ${step}`), 
+            100 * i
+        );
+    })(i);
+}

JS/04-Objects/Functions/anon.js

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+function (param1, param2) {
+    return param1 + param2;
+};
+console.log("something")

JS/04-Objects/Functions/arrow.png

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+let singleParam = parameter => console.log(parameter);
+let multiParam = (parameter,parameter2) => console.log(parameter,parameter2);
+let mutlilineArrow = (parameters)=>{
+    console.log(parameters)
+};
+

JS/04-Objects/Functions/arrows.js

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+
+
+function closureScoped(job) {
+  if (job=="designer") {
+    return (name)=>console.log(`my name is ${name} my job is ${job}`) 
+  }
+  else if (job=="teacher") {
+    return (name)=>console.log(`my name is ${name} my job is ${job}`) 
+  }
+  else {
+    return (name)=>console.log(`my name is ${name} my job is ${job}`) 
+  }
+}
+closureScoped("designer")("hans");
+
+function curryingClosure(job){
+  return function(name) {
+    if (job=="Teacher")
+        console.log(` ${name} can you explain closures? ${job}`) 
+    else if (job=="javaScripter")
+        console.log(`${name} can explain closure and currying because he is a ${job}`) 
+    else
+        console.log(`${name} what is your malfunction?`) 
+  }
+}
+
+curryingClosure("javaScripter")("hans")

JS/04-Objects/Functions/closures.js

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+function getRectArea(width, height) {
+    if (width > 0 && height > 0) {
+      console.log(width * height)
+      return width * height;
+    }
+    console.log(0)
+    return 0;
+  }
+  
+
+  getRectArea(3, 4)   // 12
+  getRectArea(-3, 4)  // 0
+  // console.log(getRectArea(3, 4)); // 12
+  // console.log(getRectArea(-3, 4)); // 0