TypeScript 2.x By Example

The var keyword

Variables declared with the var keyword have a global scope in which they are declared; this means that they can be accessed by any function sharing the same scope. The following example shows the scope of the variable value in innerFunction:

Also, variables declared with the var keyword are subject to hoisting. This means that if we declare a variable at the end of a function, the runtime will hoist it to the top and we will not have any error if we would have used that variable before being declared. In the following example, we see an example of hoisting. Although the value variable was declared at line 9, we were able to ...