Core Basics Blog

The globalThis object is a relatively new addition to the JavaScript language, introduced in ECMAScript 2020. It provides a standardized way to access the global object across different environments, such as browsers, Node.js, and web workers. In this article, we'll explore the globalThis object in TypeScript, its benefits, and how to use it effectively. What is the globalThis Object? The globalThis object is a property of the global object that refers to itself. It's a way to access the global object without using the this keyword or the window object in browsers. The globalThis object is supported in modern browsers, Node.js, and web workers. Why Do We Need globalThis? Before the introduction of globalThis, accessing the global object was not straightforward. In browsers, you could use the window object, but this approach wouldn't work in Node.js or web workers. In Node.js, you could use the global object, but this wouldn't work in browsers. The globalThis...

TypeScript, like JavaScript, uses a variety of unique symbols to represent different concepts and operations. These symbols are used to define the syntax and structure of the language, and are essential for writing effective and efficient code. Arithmetic Operators TypeScript supports a range of arithmetic operators, including: + (addition) - (subtraction) * (multiplication) / (division) % (modulus) ** (exponentiation) // Example usage: let x = 5; let y = 3; console.log(x + y); // Output: 8 console.log(x - y); // Output: 2 console.log(x * y); // Output: 15 console.log(x / y); // Output: 1.6666666666666667 console.log(x % y); // Output: 2 console.log(x ** y); // Output: 125 Comparison Operators TypeScript also supports a range of comparison operators, including: == (equality) != (inequality) === (strict equality) !== (strict inequality) > (greater than) < (less than) >= (greater than or equal to) <= ...

TypeScript is a statically typed language that aims to help developers catch errors early and improve code maintainability. However, there are situations where the type of a value is unknown or cannot be determined at compile time. This is where the unknown type comes into play. What is the Unknown Type? The unknown type is a type in TypeScript that represents a value that is not known at compile time. It is similar to the any type, but with some key differences. Unlike the any type, which allows you to assign any value to a variable, the unknown type is more restrictive and requires explicit type checking before assigning a value to a variable. Key Differences Between Unknown and Any Here are the key differences between the unknown and any types in TypeScript: Assignability**: The any type is assignable to any other type, whereas the unknown type is only assignable to the any type and the unknown type itself. Type Checking**: The any type bypasses type checking, wh...

TypeScript is a statically typed language that allows developers to catch errors early and improve code maintainability. One of its key features is type inference, which enables the compiler to automatically infer the types of variables, function return types, and other expressions. In this article, we'll delve into the world of type inference in TypeScript, exploring how it works, its benefits, and best practices for using it effectively. What is Type Inference? Type inference is the process by which the TypeScript compiler automatically determines the types of variables, function return types, and other expressions based on their usage. This means that you don't always need to explicitly specify the types of your variables or function return types. Instead, the compiler can infer them for you, making your code more concise and easier to write. How Does Type Inference Work? TypeScript's type inference algorithm works by analyzing the code and making educated gu...

The global object is a fundamental concept in JavaScript and TypeScript, serving as the top-level scope for variables, functions, and other declarations. In this article, we'll delve into the world of the global object in TypeScript, exploring its properties, methods, and best practices for working with it. What is the Global Object? The global object is the highest-level scope in a JavaScript or TypeScript program. It's the object that contains all global variables, functions, and other declarations. In a browser environment, the global object is typically the `window` object, while in a Node.js environment, it's the `global` object. Properties of the Global Object The global object has several properties that are accessible from anywhere in the program. Some of the most commonly used properties include: NaN : Not a Number, a special value that represents an invalid or unreliable result. Infinity : A special value that represents infinity. undefined ...

TypeScript provides several utility types that help developers create more robust and maintainable code. One such utility type is the Record type. In this article, we will explore the Record type in TypeScript, its syntax, and how to use it effectively. What is the Record Type? The Record type is a utility type in TypeScript that allows you to create an object type with a specific set of properties. It is similar to the object type, but it provides more flexibility and control over the properties of the object. Syntax The syntax for the Record type is as follows: type Record<K, T> = { [P in K]: T; } In this syntax, K is the type of the keys, and T is the type of the values. The Record type creates an object type with properties of type T, where the keys are of type K. Example Usage Let's consider an example where we want to create an object type with string keys and number values. We can use the Record type as follows: type StringNumberRecord = Recor...

Tuples are a fundamental data structure in TypeScript, allowing developers to store and manipulate collections of values of different types. In this article, we will delve into the world of tuples in TypeScript, exploring their syntax, usage, and benefits. What are Tuples in TypeScript? In TypeScript, a tuple is an array-like data structure that can store a fixed number of elements of different types. Unlike arrays, which can store elements of the same type, tuples can store elements of different types. Tuples are useful when you need to store a small collection of values that are related to each other. Tuple Syntax The syntax for creating a tuple in TypeScript is as follows: let tupleName: [type1, type2, type3] = [value1, value2, value3]; In the above syntax: tupleName is the name of the tuple. [type1, type2, type3] is the type annotation for the tuple, specifying the types of the elements. [value1, value2, value3] is the initialization of the tuple with...

TypeScript is a statically typed, multi-paradigm programming language developed by Microsoft. It is designed to help developers catch errors early and improve code maintainability, thus making it a popular choice for large-scale JavaScript applications. One of the key features of TypeScript is its support for namespaces, which help organize and structure code in a more efficient way. In this article, we will delve into the concept of namespaces in TypeScript and explore how to use the namespace keyword effectively. What are Namespaces in TypeScript? In TypeScript, a namespace is a way to group related classes, interfaces, functions, and variables under a single name. This helps to avoid naming conflicts and makes it easier to organize and structure code. Namespaces are also known as internal modules in TypeScript. Why Use Namespaces in TypeScript? There are several reasons why you might want to use namespaces in TypeScript: Avoid naming conflicts: Namespaces help to av...

TypeScript provides several utility types that help developers create more robust and maintainable code. One of these utility types is the omit type, which allows you to create a new type by excluding certain properties from an existing type. In this article, we'll explore the omit utility type in TypeScript, its syntax, and how to use it effectively. What is the Omit Utility Type? The omit utility type is a part of the TypeScript standard library. It's used to create a new type that excludes certain properties from an existing type. The omit type takes two type parameters: the type to omit properties from and the properties to omit. type Omit<T, K> = Pick<T, Exclude<keyof T, K>>; In this syntax, T is the type to omit properties from, and K is the type of properties to omit. Example Usage of Omit Let's consider an example to understand how the omit utility type works. Suppose we have a type called Person with properties name , age ...

TypeScript is a statically typed language that provides several utility types to help developers write more expressive and maintainable code. In this article, we'll explore the different utility types available in TypeScript and provide guidance on how to choose the right one for your use case. What are Utility Types? Utility types are a set of generic types that can be used to manipulate and transform other types. They are called "utility" types because they provide a way to perform common type transformations and manipulations in a reusable and composable way. 1. Partial Type The `Partial` type is used to create a new type that represents a subset of the properties of an existing type. It is often used to create a type that represents a partial or incomplete version of an object. interface User { name: string; age: number; } type PartialUser = Partial<User>; const user: PartialUser = { name: 'John Doe', }; 2. Readonly Type The `R...

TypeScript is a statically typed, multi-paradigm programming language developed by Microsoft. It is designed to help developers catch errors early and improve code maintainability, thus making it a popular choice for large and complex applications. One of the key features of TypeScript is its support for object-oriented programming (OOP) concepts, including interfaces and classes. In this article, we will explore how to implement the 'implements' keyword in TypeScript. What is the 'implements' Keyword? The 'implements' keyword is used in TypeScript to specify that a class implements an interface. An interface is a blueprint of a class, defining the properties, methods, and their signatures that a class must implement. When a class implements an interface, it must provide an implementation for all the members of the interface. Example of Implementing an Interface // Define an interface interface Printable { print(): void; } // Implement the interf...

The yield keyword in TypeScript is a powerful tool for creating iterators and generators. It allows developers to produce a series of values over time, rather than computing them all at once and returning them in an array. In this article, we'll explore the yield keyword in depth, including its syntax, use cases, and best practices. What is the Yield Keyword? The yield keyword is a reserved word in TypeScript that is used to produce a value in a generator function. When a generator function is called, it returns an iterator object that can be used to iterate over the values produced by the function. The yield keyword is used to specify the values that are produced by the generator function. Syntax The syntax for using the yield keyword in TypeScript is as follows: function* generatorFunction() { yield value1; yield value2; yield value3; } In this example, the generatorFunction function uses the yield keyword to produce three values: value1, value2, and value3...

TypeScript is a statically typed, multi-paradigm programming language developed by Microsoft. It is designed to help developers catch errors early and improve code maintainability, thus making it a popular choice for large and complex applications. One of the key features of TypeScript is its support for object-oriented programming (OOP) concepts, including interfaces and classes. In this article, we will explore how to implement the 'implements' keyword in TypeScript. What is the 'implements' Keyword? The 'implements' keyword is used in TypeScript to specify that a class implements an interface. An interface is a blueprint of a class, defining the properties, methods, and their signatures that a class must implement. When a class implements an interface, it must provide an implementation for all the members of the interface. Example of Implementing an Interface // Define an interface interface Printable { print(): void; } // Implement the interf...

The keyof operator in TypeScript is a powerful tool that allows developers to create type-safe and flexible code. It's used to represent the union of a type's property keys. In this article, we'll delve into the world of keyof, exploring its syntax, use cases, and benefits. What is the keyof Operator? The keyof operator is a type operator in TypeScript that takes a type as an argument and returns a type that represents the union of the property keys of that type. It's denoted by the keyof keyword followed by a type in angle brackets. interface Person { name: string; age: number; } type PersonKeys = keyof Person; // type PersonKeys = "name" | "age" In the example above, the keyof operator is used to create a type called PersonKeys, which represents the union of the property keys of the Person interface. The resulting type is a union of string literals, "name" and "age", which are the property keys of the Person in...

The while loop is a fundamental control structure in programming that allows you to execute a block of code repeatedly as long as a certain condition is met. In this article, we'll delve into the world of while loops in TypeScript, exploring their syntax, usage, and best practices. What is a While Loop? A while loop is a type of loop that continues to execute a block of code as long as a specified condition is true. The loop consists of a condition and a body, where the body is executed repeatedly until the condition becomes false. Syntax of a While Loop in TypeScript The syntax of a while loop in TypeScript is as follows: while (condition) { // code to be executed } In this syntax: condition is a boolean expression that is evaluated before each iteration of the loop. code to be executed is the block of code that is executed repeatedly as long as the condition is true. Example of a While Loop in TypeScript Let's consider a simple example of a w...

The with statement is a feature in JavaScript that allows you to extend the scope chain for a statement. It is not recommended to use this statement in TypeScript or JavaScript, as it can lead to confusing and hard-to-debug code. However, it is essential to understand how it works and why it is generally discouraged. What is the with Statement? The with statement is used to extend the scope chain for a statement. It allows you to access properties and methods of an object without having to specify the object name. The syntax for the with statement is as follows: with (expression) { // statements } In this syntax, the expression is the object whose properties and methods you want to access. The statements inside the with block can access the properties and methods of the object without having to specify the object name. Example of the with Statement Here is an example of using the with statement: const person = { name: 'John Doe', age: 30, occup...

TypeScript is a statically typed, multi-paradigm programming language developed by Microsoft. It is designed to help developers catch errors early and improve code maintainability, thus making it a popular choice for large-scale JavaScript applications. One of the fundamental concepts in TypeScript is the use of keywords to declare variables. In this article, we will delve into the 'var' keyword in TypeScript, exploring its usage, limitations, and best practices. What is the 'var' Keyword in TypeScript? The 'var' keyword is used to declare a variable in TypeScript. It is a part of the language's syntax and is used to store values in a variable. The 'var' keyword is similar to the 'let' and 'const' keywords, but it has some key differences. Declaring Variables with 'var' To declare a variable using the 'var' keyword, you can use the following syntax: var variableName: type = value; Here, 'variableNa...