lesson 2

nodeJS/Learning/01/index.js

@@ -85,4 +85,255 @@ console.log(x);
 
 //Null: telling them theres nothing in the code
 let y = null;
-console.log(y);
+console.log(y);
+
+//Non-primitive data type: anything thats not within the box//
+//Object, Array, Function//
+
+//Object: sth to define a list of things, e.g. list of primitive data types//
+// const or let -> {curly}, can contain diff. data types
+
+const user = {
+    name1: "John",
+    age: 5,
+    verified: true,
+
+    //Nested object (within the object)
+    address: {
+        city: "New York",
+        state: "NY",
+    }
+}
+
+console.log(user)
+console.log(user.address.state)
+
+//Array: a list of primitive data types within one category, only one type of data
+const fruits = ["Apple", "Banana", "Cherry", "Dates"];
+const numbers = [1, 2, 3, 4, 5];
+
+//Array, has string indexing stuff
+console.log(fruits[2]) // Cherry
+
+//Function
+// y = f(x) = 2x + 1
+// y -output, x-input
+
+function add(x) {
+    return 2*x + 1;
+}
+
+add (5);
+console.log(add(5)); //11
+
+//greet is the function name
+// ${}: must use `(next to 1)
+function greet(name) {
+    return `Hello, ${name}`;
+}
+console.log(greet('Tiffany')); // Hello Tiffany
+
+let functionName = function(x) {
+    return 2*x + 1;
+}
+
+//best practice to declare a function
+const arrowFunction = (x) => {
+    return 2*x + 1;
+}
+
+//Operators, things we can do with the data types
+
+//Arithmetic operators
+// e.g. + - * / ++ --
+
+let a = 10;
+let b = 5;
+
+console.log(a + b); //15
+console.log(a - b); //5
+console.log(a * b); //50
+console.log(a/b); //2
+console.log(a % b) //0 (remainder of division)
+console.log(a++); //11 (a = a + 1)
+console.log(a--); //9 (a = a-1)
+
+//Assignment operators
+// =, +=, -=, *=, /=, %=
+
+let c = 10
+let d = 5
+
+c += d; //c = c + d
+
+//Comparison operators, comparing stuffs
+// ==, !=, >, <, >=, <=, ===, !==
+
+let e = "10"
+let f = 10
+
+console.log(e == f); // false (is e equal to f)
+
+console.log(e === f) //false, absolutely equal to, which it is not, but if ==
+
+//Logical Operators
+//&&(AND), ||(OR), ! (NOT)
+
+let g = 10;
+let h = 5;
+
+console.log(g > 5 && h > 10); //false
+console.log(g > 5 || h > 10); //true
+console.log(!(g > 5)); //false, just reverse whats inside
+
+//Control structures
+//If statements
+
+// if (condition) {
+//     //result
+// }
+
+let i = 2;
+
+if (i > 5) {
+    console.log("I am smart")
+}
+
+//If-Else statement
+let j = 10;
+
+if (j > 5) {
+    console.log("Ronald believes in Tiffany's religion")
+} else {
+    console.log("Ronald does not believe in Tiffany's religion")
+}
+
+// If Else If statement
+let k = 10
+
+if (k > 5) {
+    console.log("k is larger than 5");
+} else if (k < 5) {
+    console.log("k is less than 5");
+} else if (k === 5) {
+    console.log("k is equal to 5");
+} else {
+    console.log("k is not a number");
+}
+
+//Different way to announce if statement, ternary operator
+
+let n = 10;
+//condition ?(if) expression1(true) : expression 2(false)
+n > 5 ? console.log("n is greater than 5") : console.log("n is smaller than 5");
+
+// Switch statement
+let day = "Monday";
+
+switch(day) {
+    case "Monday":
+        console.log("Today is Monday \:\(")
+        break;
+    case "Tuesday":
+        console.log("Today is Tuesday")
+        break;
+    default:    
+        console.log("No day")
+        break;
+}
+
+// switch(condition) {
+//   case value1:
+//     //code block
+//     break; (end of this case)
+//   case value2:
+//     //code block
+//     break;
+//   default:
+//     //code block
+//     break;
+// }
+
+
+
+//Loops, usually a number to loop
+
+// For Loop
+// for (initialization; condition; increment/decrement) {
+// //code block
+//  }
+
+for (let i = 0; i < 5; i++) {
+    console.log("Tiffany is smart");
+}
+
+// While Loop, anything within the condition, if it's still true, will keep running
+// while(condition) {
+// // code block
+// }
+
+let m = 0;
+
+while (m<5) {
+    console.log("Tiffany is smart");
+    m++;
+}
+
+// For In Loop, comma within object (for objects)
+let person2 = {
+    name: "Tiffany",
+    age: 24,
+    isSmart: true,
+}
+
+//key can be any name, eg color, looping the list
+for (let key in person2) {
+    console.log(key, person2[key]);
+}
+
+// For of Loop (for arrays)
+let numbers1 = [1, 2, 3, 4, 5]
+
+for (let number of numbers1) {
+    number += 1; // number= number + 1 
+    console.log(number);
+}
+
+//Do While Loop
+
+//do {
+// // code block
+// } while (condition);
+
+let happy = 0
+
+do {
+    console.log("Tiffany is the savior");
+    happy++;
+} while (happy < 5)
+
+//looping "tiffany is the savior" using happy (plus 1 for each round)
+// until happy reaches a number larger than 5
+
+// Classes: recipe book or instruction
+//constructor, like ingredients
+
+class bread {
+    constructor(flour, water, salt) {
+        this.flour = flour;
+        this.water = water;
+        this.salt = salt;
+    }
+
+    bake() {
+        console.log(`Baking Bread with ${this.flour}, using ${this.water} cups of water and ${this.salt} tsp of salt.`);
+    }
+}
+const bread1 = new bread("wheat", 2, 3)
+
+bread1.bake()
+
+// Modules: it only happens in a modules
+
+//Import
+//import {greet} from "./greet.js";