What is the difference between let and var?

In Swift, let and var are used to declare constants and variables, respectively. The main difference between the two lies in mutability: let is used for constants that cannot be changed after they are assigned, while var is used for variables that can be modified later in the program.

Here is a brief breakdown:

let - used for a constant value that cannot change.
var - used for a variable value that can change.

For example:


        let constantValue = 10 // This value cannot be changed
        var variableValue = 20 // This value can be changed
        variableValue = 30 // Now variableValue is 30