Contenu du cours
Introduction to JavaScript
Introduction to JavaScript
1. Getting Started
First Javascript Console ApplicationChallenge: Showing some OutputChallenge: Outputing Multiple LinesDealing with NumbersChallenge: Working with NumbersChallenge: Calculating the Speed of a CarChallenge: Calculating Area of a TrapeziumOutputting Multiple ValuesChallenge: Consoling Meaningful OutputHow to Use Comments in Javascript?Challenge: Adding a CommentMulti-Line CommentsChallenge: Commenting out CodeWhat Is JavaScript anyway?
2. Manipulating Data
Storing DataChallenge: Declaring a VariableChallenge: Accessing Data From a VariableChallenge: Fixing Variable NamesChallenge: Reassigning a VariableConstantsChallenge: Declaring & Using ConstantsPerforming Arithmetic On VariablesChallenge: Making a Salary CalculatorChallenge: Adjusting Salary with a BonusExploring Primitive Data TypesChallenge: Declaring a Boolean ValueHow different Data Types InteractChallenge: Concatenating StringsChallenge: Creating User Profile & Activity Details
3. Conditional Statements
Comparison OperatorsChallenge: Checking Age EligibilityThe `if` StatementChallenge: Weather-Based Outfit RecommenderChallenge: Even or OddNested Conditional StatementsThe `else` ClauseChallenge: Improving Even or Odd CheckerChallenge: Temperature AdvisorThe `else if` ClauseChallenge: Grade Categorizer` AND` Logical OperatorChallenge: Checking if a Number is Even and PositiveOR Logical OperatorChallenge: Accessing Control System
4. Mastering Functions
What Are Functions?Challenge: Simple FunctionChallenge: Calculating the Speed of a CarScopesPassing Data into FunctionsChallenge: Fixing the Speed FunctionChallenge: Improving the Grade CategorizerTask: Defining a Compound FunctionReturning Data from FunctionsDefault ValuesChallenge: Email Auto-Responder with Default Parameters
5. Exploring Arrays
What Are Arrays?Challenge: Defining An ArrayChallenge: IndexingAdding Values to an ArrayChallenge: Pushing Elements to an ArrayRemoving Elements from an ArrayChallenge: Practicing `pop` & `shift`The `length` PropertyChallenge: Counting ElementsThe `includes` MethodChallenge: Searching for Animals in the Zoo
The `includes` Method
The includes method can be used to quickly determine of a specific element exists in the array or not.
Following is the general syntax of the includes method:
python
The includes method returns a boolean (true or false) value based on whether or not the element exists in the array.
Returns
trueif the element is found;Returns
falseif the element is not found.
let itemsInStock = ["Laptop", "Phone", "Tablet", "Charger"]; console.log(itemsInStock.includes("Phone")); console.log(itemsInStock.includes("Headphones"));
Note
The includes method performs a strict comparison (===), meaning it checks for exact matches, including case sensitivity. For example, itemsInStock.includes("phone") would return false because "phone" (lowercase) is not the same as "Phone" (uppercase "P").
1. What will be the output of the following code?
2. Which of the following statements is true about the includes method?
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Section 5. Chapitre 10
