JavaScript syntax quick reference guide

If you know the basics of JavaScript, you can skip this section. Here is a quick overview of JavaScript:

Use the keyword var to define a variable:
```
var myAge = 31;
```

Use // for inline comments and /* */ for multiline comments:

// this is an inline comment
/* this
is a
multi-line
comment
*/

Conditional statements:

if (myAge > 29) {
  console.log("I am not in my twenties anymore!");
} else {
  console.log("I am still in my twenties!");
}

Defining a function:

function nameOfMyFunction(argument1, argument2) {
  console.log(argument1, argument2);
}

Executing a function:

nameOfMyFunction("First Value", "Second Value");

A function can also behave as a class and have methods, properties, and instances. Properties are accessed through the keyword this:
```
function Car(maxSpeed) {
  this.maxSpeed = maxSpeed;
  this.currentSpeed = 0;
}
```

The standard way to create a prototyped method for a function in JavaScript is by using the property prototype:

Car.prototype.brake = function() {
  if (this.currentSpeed > 0) {
    this.currentSpeed -= 5;
  }
};

Car.prototype.accelerate = function() {
  if (this.currentSpeed < this.maxSpeed) {
    this.currentSpeed += 5;
  }
};

To create an instance of a class in JavaScript, use the keyword new:

var car = new Car(100);
car.accelerate();
car.accelerate();
car.brake();

Arrays and objects:
```
var myArray = [];
var myObject = {};
```

Callbacks in JavaScript:

var friends = ["Karalyn", "Patrik", "Bernardo"];
friends.forEach(function (name, index) {
  console.log(index + 1, name); // 1 Karalyn, 2 Patrik, 3 Bernardo
});

A callback in this example is an anonymous function that is passed to another function as a parameter, so it is called (or executed) inside the other function. As you can see in the preceding example, the forEach array method expects a callback function. It executes the provided callback once for each element in the array. It is very common to find asynchronous functions/methods that expect callbacks in JavaScript.

If you want to know more about JavaScript syntax and features, we recommend the Mozilla Developer Network website at https://developer.mozilla.org/en-US/docs/Web/JavaScript.

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Redis Essentials

By : Maxwell Dayvson da Silva

Redis Essentials

By: Maxwell Dayvson da Silva

Overview of this book

JavaScript syntax quick reference guide

Redis Essentials

By : Maxwell Dayvson da Silva

Redis Essentials

By: Maxwell Dayvson da Silva

Overview of this book

JavaScript syntax quick reference guide

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