JavaScript Fundamentals

JavaScriptBasics/FoundationP4.md

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+Using arrays.
+Using built-in array methods.
+Using loops.
+Getting your hands dirty with TDD exercises.
+
+
+
+####1. Using arrays:
+Overview:
+Arrays are used to store multiple values in a single variable.
+They are ordered, indexed, and can hold various data types.
+Arrays provide methods for manipulation and iteration.
+Declaration:
+```
+// Example:
+var fruits = ["Apple", "Banana", "Orange"];
+```
+
+#### 2. Using built-in array methods:
+Overview:
+JavaScript provides built-in methods for working with arrays.
+Common methods include push, pop, shift, unshift, splice, slice, forEach, map, filter, etc.
+Example:
+```
+// Adding elements to the end of an array
+fruits.push("Mango");
+
+// Removing the last element
+var removedFruit = fruits.pop();
+
+// Iterating over elements
+fruits.forEach(function(fruit) {
+  console.log(fruit);
+});
+```
+
+### 3. Using loops:
+Overview:
+Loops are used to repeatedly execute a block of code.
+Common loop types are for, while, and do-while.
+Loops help iterate over arrays or perform tasks a specific number of times.
+```
+// For loop
+for (var i = 0; i < fruits.length; i++) {
+  console.log(fruits[i]);
+}
+
+// While loop
+var i = 0;
+while (i < fruits.length) {
+  console.log(fruits[i]);
+  i++;
+}
+```
+
+### 4. Getting your hands dirty with TDD exercises:
+
+Overview:
+Test-Driven Development (TDD) is a software development approach where tests are written before the code.
+It involves three steps: writing a failing test, writing the minimum code to pass the test, and then refactoring.
+
+Examples:
+Assume we are building a simple function to add two numbers.
+Step 1: Write a Failing Test
+```
+// Test Case
+test("Adding 2 + 3 should return 5", function() {
+  assert.equal(add(2, 3), 5);
+});
+```
+Step 2: Write Minimum Code to Pass the Test
+```
+// Function Implementation
+function add(a, b) {
+  return a + b;
+}
+```
+Step 3: Refactor (if needed)
+Refactor the code to improve readability or performance while ensuring the test still passes.
+This cycle continues as you add more features or make changes, ensuring that your code remains reliable.
+
+
+____
+
+### 1 . What is an array?
+
+Definition:
+An array is a data structure in JavaScript that allows you to store and organize multiple values under a single variable.
+```
+var fruits = ["Apple", "Banana", "Orange"];
+```
+
+### 2. What are arrays useful for?
+Overview:
+Arrays are useful for storing and managing collections of data.
+They provide an ordered and indexed structure for elements.
+
+### 3. How do you access an array element?
+Accessing Elements:
+Use square brackets [] with the index to access array elements. Indexing starts from 0.
+Example:
+```
+var firstFruit = fruits[0]; // Accessing the first element ("Apple")
+
+
+```
+
+### 4. How do you change an array element?
+Modifying Elements:
+Use the index to access the element and assign a new value.
+Example:
+```
+fruits[1] = "Grapes"; // Changing the second element to "Grapes"
+
+```
+### 5. What are some useful array properties?
+Useful Properties:
+length: Returns the number of elements in the array.
+Example:
+```
+var arrayLength = fruits.length; // Returns the length of the array (3)
+
+```
+
+### 6. What are some useful array methods?
+Useful Methods:
+push, pop, shift, unshift, splice, slice, forEach, map, filter, etc.
+Example:
+```
+fruits.push("Mango"); // Adds "Mango" to the end of the array
+```
+
+### 7. What are loops useful for?
+Overview:
+Loops are useful for executing a block of code repeatedly.
+They are handy for iterating over array elements or performing repetitive tasks.
+
+### 8. What is the break statement?
+Break Statement:
+The break statement is used to exit a loop prematurely.
+Example:
+```
+for (var i = 0; i < 10; i++) {
+  if (i === 5) {
+    break; // Exits the loop when i is 5
+  }
+  console.log(i);
+}
+
+```
+### 9. What is the continue statement?
+Continue Statement:
+The continue statement skips the current iteration of a loop and moves to the next one
+```
+for (var i = 0; i < 5; i++) {
+  if (i === 2) {
+    continue; // Skips the iteration when i is 2
+  }
+  console.log(i);
+}
+
+```
+
+### 10. What is the advantage of writing automated tests?
+
+###### Advantages of Automated Tests:
+Detect and prevent software bugs early in the development process.
+Ensure code changes don't introduce new issues (regression testing).
+Improve code quality and maintainability.
+Facilitate collaboration among team members.
+Provide documentation for expected behavior.
+Boost confidence in making changes and refactoring code.
+