Mastering TypeScript Access Modifiers

Understanding TypeScript Access Modifiers

TypeScript access modifiers are a set of keywords used to define the accessibility of class members. They determine whether a class member can be accessed by other classes or objects in the same project or even outside of it. The four access modifiers available in TypeScript are “public”, “private”, “protected”, and “readonly”. Each of these offers different levels of visibility for different classes and objects.

Public Modifier

The public modifier is the most common of all the modifiers and is the default if none is specified. This makes class members accessible from any place in the program. This includes not only other classes in the same project, but also from other projects and libraries.

Private Modifier

The private modifier restricts access to class members only within the same class. This means that they cannot be accessed from other classes in the same project or any outside source. Private access modifiers are great for creating secure code that is protected from being modified outside of its own class.

Protected Modifier

The protected modifier allows a class member to be accessed by other classes that inherit from the same class. While it does restrict access from other classes in the same project, it still allows the class member to be accessed by any descendant classes from the same project.

Readonly Modifier

The readonly modifier restricts a class member from being modified after it has been declared. Once a class member has been declared as readonly, it can only be accessed and it cannot be changed. This is great for reducing unexpected behavior when dealing with sensitive data.

TypeScript access modifiers are a great way to make sure that code is secure and cannot be modified or accessed outside of its intended purpose. They allow developers to protect class members from being accessed or changed by other programs and libraries while still allowing them to be accessible by classes in the same project.