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Introduction to JavaScript
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Conteúdo do Curso

Introduction to JavaScript

Introduction to JavaScript

1. Getting Started
Hello WorldTask - Show some OutputTask - Output Multiple LinesNumbersTask - Working with NumbersTask - Calculate the Speed of a CarTask - Calculate Area of a TrapeziumOutputting Multiple ValuesTask - Meaningful OutputCommentsTask - Adding a commentMulti-Line CommentsTask - Commenting out CodeTask - Coffee Shop SalesWhat is JavaScript anyway?
2. Manipulating Data
Storing DataTask - Declaring a VariableTask - Accessing Data From a VariableTask - Fixing Variable NamesTask - Reassigning a VariableConstantsTask - Declaring & Using ConstantsPerforming Arithmetic On VariablesTask - Making a Salary CalculatorTask - Adjusting Salary with a BonusTypes of DataTask - Declare a Boolean ValueHow different Data Types InteractTask - Concatenating StringsTask - User Profile & Activity Details
3. Conditional Statements
Comparison OperatorsTask - Checking Age Eligibility

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Performing Arithmetic On Variables

We can perform arithmetic on variables storing numbers similar to how we perform operations on raw numerical values.

For example:


              
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let varA = 10;
let varB = 20;

console.log(varA + varB);
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The expression varA + varB considers varA and varB as if they were raw numbers.

The right-hand side of the assignment statement is always evaluated before feeding the result into the variable on the left side. Because of this, we can make changes to the value of a variable:


              
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let exampleVar = 100;
console.log(exampleVar); // Before
exampleVar = exampleVar + 100;
console.log(exampleVar); // After
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This above code adds 100 to the value of exampleVar.

However, the same operation can also be performed using a shorter syntax:


              
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let exampleVar = 100;
exampleVar += 100;
console.log(exampleVar);
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This syntax works for any supported arithmetic operation.

For example:


              
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exampleVar *= 100; // Multiplication
exampleVar /= 100; // Division
exampleVar **= 100; // Raising to a Power
exampleVar %= 100; // Remainder
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A short syntax for incrementing the value of a variable by 1 is by using the ++ operator. For-example:


              
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let varA = 9;
console.log(varA); // Before
varA++;
console.log(varA); // After
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We can use -- for decrementing a variable by 1:


              
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let varA = 5;
console.log(varA); // Before
varA--;
console.log(varA); // After
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1. What will the following code output?

2. What is the purpose of the following line of code?

3. Which of the following is the correct shorthand for the operation exampleVar = exampleVar - 50?

4. What will the following code output?

question mark

What will the following code output?

Select the correct answer

question mark

What is the purpose of the following line of code?

Select the correct answer

question mark

Which of the following is the correct shorthand for the operation exampleVar = exampleVar - 50?

Select the correct answer

question mark

What will the following code output?

Select the correct answer

Tudo estava claro?

Como podemos melhorá-lo?

Obrigado pelo seu feedback!

Seção 2. Capítulo 8
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