Typescript constants are variables, whose values cannot be modified. They are block-scoped just like the let keyword. Their value cannot be changed neither they can be redeclared. Const keyword is part of the es2015 (es6) specification of the javascript.
We define variables in Typescript using let, var or const. In this article let us explore each of them and find out the difference between let vs var vs const. Knowing the difference between them is makes it easier to decide what to use where and when.
The variables have a scope or visibility. The scope of a variable determines which part of the program can access it. We can define a variable in three ways, so as to limit their visibility. One is the local variable or block variable, which has the scope of a code block (block scope or local scope). The second one is a function variable or class variable which has the function/class scope. The last one is the global variable, which can be accessed anywhere in the program (global scope).
Variable Scope in TypeScript : Global, Local & function Read More »
We must give a name to variables, functions, arrays, classes, interfaces, etc so as to identify them. Hence, typescripts call them as an Identifiers. We then use the identifier to refer to the variable, functions, etc elsewhere in the program. There are certain rules & restrictions that need to be followed when we name and identifier. Since the Typescript compiles to javascript. it follows all of the javascript naming rules. Also, the reserved keywords must not be used as an identifier name.
A Typescript variable is a storage for the data, where programs can store value or information. We must give a name to the variable. We can then refer the variable in another part of the program. In this article, we learn how to declare a variable. Also, learn about the rules for naming the variable.
