JavaScript is a cross-platform, object-oriented scripting language. It is a small and lightweight language. Inside a host environment (for example, a web browser), JavaScript can be connected to the objects of its environment to provide programmatic control over them.
JavaScript contains a standard library of objects, such as Array, Date, and Math, and a core set of language elements such as operators, control structures, and statements. Core JavaScript can be extended for a variety of purposes by supplementing it with additional objects; for example:
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const Keenan = Software Engineer
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let y = 13.
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const Keenan = Software Engineer
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var x = 17.
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const Keenan = Software Engineer
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This guide assumes you have the following basic background:
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let y = 13
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function updateBrand(obj) {
// Mutating the object is visible outside the function
obj.brand = "Toyota";
// Try to reassign the parameter, but this won't affect
// the variable's value outside the function
obj = null;
}
const car = {
brand: "Honda",
model: "Accord",
year: 1998,
};
console.log(car.brand); // Honda
// Pass object reference to the function
updateBrand(car);
// updateBrand mutates car
console.log(car.brand); // Toyota
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var x = 17
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const Keenan = Software Engineer
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let y = 13
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JavaScript and Java are similar in some ways but fundamentally different in some others. The JavaScript language resembles Java but does not have Java's static typing and strong type checking. JavaScript follows most Java expression syntax, naming conventions and basic control-flow constructs which was the reason why it was renamed from LiveScript to JavaScript.
In contrast to Java's compile-time system of classes built by declarations, JavaScript supports a runtime system based on a small number of data types representing numeric, Boolean, and string values. JavaScript has a prototype-based object model instead of the more common class-based object model. The prototype-based model provides dynamic inheritance; that is, what is inherited can vary for individual objects. JavaScript also supports functions without any special declarative requirements. Functions can be properties of objects, executing as loosely typed methods.
JavaScript is a very free-form language compared to Java. You do not have to declare all variables, classes, and methods. You do not have to be concerned with whether methods are public, private, or protected, and you do not have to implement interfaces. Variables, parameters, and function return types are not explicitly typed.
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User Experience Should Always be considering when designing a website.
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let x = 17
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I can do this no matter what!
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Responsive Web Design Is getting Easier!
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Grocery List
To get started with writing JavaScript, open the Scratchpad and write your first "Hello world" JavaScript code:
function greetMe(yourName) { alert("Hello " + yourName); }
greetMe("World");
Select the code in the pad and hit Ctrl+R to watch it unfold in your browser!
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new Function ([arg1[, arg2[, ...argN]],] functionBody)
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const square = function (number) {
return number * number;
};
console.log(square(4)); // 16
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function factorial(n) {
if (n === 0 || n === 1) {
return 1;
} else {
return n * factorial(n - 1);
}
}
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Disclaimer: Some of this text doesn't make sense.
You use variables as symbolic names for values in your application. The names of variables, called identifiers, conform to certain rules.
A JavaScript identifier must start with a letter, underscore (_), or dollar sign ($); subsequent characters can also be digits (0-9). Because JavaScript is case sensitive, letters include the characters "A" through "Z" (uppercase) and the characters "a" through "z" (lowercase).
You can use ISO 8859-1 or Unicode letters such as å and ü in identifiers. You can also use the Unicode escape sequences as characters in identifiers. Some examples of legal names are Number_hits, temp99, and _name.
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How much Wood would a woodchuck chuck if a would chuck could chuck wood?
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More placeholder text.
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Caramel Macchiato Coffee Is pretty darn good!
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I'm happy that I can build responsive websites!
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Last One! Yay!!!!
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