- 5 Is Let better than VAR?
- 6 Should I use VAR or let?
- 8 What’s the difference between VAR and let Swift?
- 11 Why you should stop using var?
- 13 Can I use VAR in Java?
let allows you to declare variables that are limited to the scope of a block statement, or expression on which it is used, unlike the var keyword, which declares a variable globally, or locally to an entire function regardless of block scope.
With var it’s still possible as JS when it compiles all scripts it stack declaration of all variables to the very top of the global script, and only assigns value when script triggers the block of code where variable is declared.
Is Let better than VAR?
The main difference is the scope difference, while let can be only available inside the scope it’s declared, like in for loop, var can be accessed outside the loop for example. From the documentation in MDN (examples also from MDN):
Should I use VAR or let?
As a general rule, you should always declare variables with const, if you realize that the value of the variable needs to change, go back and change it to let. Use let when you know that the value of a variable will change. Use const for every other variable. Do not use var.
What are infinite loops? An infinite loop is a piece of code that keeps running forever as the terminating condition is never reached. An infinite loop can crash your program or browser and freeze your computer.
What’s the difference between VAR and let Swift?
Both let and var are for creating variables in Swift. let helps you create immutable variables (constants) while on the other hand var creates mutable variables. The difference between them is that when you create a constant using let you have to assign something to it before the first use and can’t reassign it.
Why you should stop using var?
Closures. This one’s hard to understand if it’s a new concept, but a closure is a function that references a free variable. When we have a closure with a var variable, the reference is remembered, which can be troublesome when inside a loop where that variable changes.
When you use var, you are instantiating a variable in the current scope. This will also prevent access of variables named the same in higher scope, within the current scope.
Can I use VAR in Java?
In Java, var can be used only where type inference is desired; it cannot be used where a type is declared explicitly. If val were added, it too could be used only where type inference is used. The use of var or val in Java could not be used to control immutability if the type were declared explicitly.