Variables are the foundation of all programming languages. Variables are used to store data such as strings of text, integers, and so on. The variables' data or values can be set, modified, and retrieved as needed. Variables, in general, are symbolic names for values.
The var keyword is used to create variables, whereas the assignment operator (=) is used to assign values to variables, as shown below: value = var varName;
The let declaration declares a block-scoped local variable and optionally sets its value.
In contrast to the var keyword, which declares a variable globally or locally to an entire function regardless of block scope, let allows you to define variables that are confined to the scope of the block statement or expression on which it is used.
Another distinction between var and let is that the latter may only be accessed after its declaration. As a result, let statements are frequently viewed as non-hoisted.
In contrast to the var keyword, which declares a variable globally or locally to an entire function regardless of block scope, let allows you to define variables that are confined to the scope of the block statement or expression on which it is used. Another distinction between var and let is that the latter may only be accessed after its declaration. As a result, let statements are frequently viewed as non-hoisted.
Constants created with the const declaration are block-scoped, similar to variables declared with the let keyword. A constant's value cannot be modified by reassignment or redeclared. If a constant is an object or array, its properties or items, however, can be updated or removed.
This declaration generates a constant with a global or local scope to the block in which it is defined. Global constants, unlike var variables, do not become window object attributes. The const declaration returns a value that is read-only. It does not imply that the value it contains is immutable; rather, the variable identifier cannot be changed. For example, if the content is an object, this indicates that the object's contents (e.g., its properties) can be changed.