🐢 Difference Between Var And Val

A variable declared with `var` is mutable. A variable declared with `val` is immutable. A variable declared with `const` is immutable. Values are assigned at run time. Values are assigned at run time. Values are assigned at compile time. A variable declared with `var` can be assigned primitive data types. A variable declared with `val` can be In the above examples, val y and def z return the same value. However, a def is evaluated when it is called, whereas a val or var is evaluated when it is assigned. This can result in differing behavior when the definition has side effects: scala> val a = {println ("Hi"); 1} Hi a: Int = 1 scala> def b = {println ("Hi"); 1} b: Int scala> a + 1 1. Overview. In this tutorial, we’ll explore the similarities and differences between methods, variables, values, and lazy values. For more information on Scala’s core features, refer to our Intro and Guide to lazy val. 2. Methods. Methods are lazily evaluated, which means their evaluation is delayed until we call them. This is a read-only value. var is a mutable value. const would on the other hand be not 100% correct. The value PI (3.14..) is a constant. Its value never changes. The value of x in this line val x = random.nextInt () will (hopefully) always be different, but you want the value not to be modified in the function. Dynamic are dynamically typed variables. The following is the syntax for declaring a dynamic type −. dynamic = value; The following is an example −. dynamic val1 = 100; dynamic val2 = 5; dynamic val3 = 20; The dynamic types are similar to object types except that type checking for object type variables takes place at compile set variable value does not assign a value to the variable variable, the syntax for that would be variable=value. What the set command does is to replace the parameters of the script (or function). When you run a script with arguments, these are available in the script in special variables that have a number rather than a name: $1, $2 If we want to be able to modify a property’s value, we mark it with the var keyword. If we want an immutable property, we mark it with a val keyword. The main difference is that val properties can’t have setters. A consequence of defining custom getters is that a val property can actually change its value. Accordingly, the main difference between the two is that val declares an immutable variable (i.e., a variable that cannot be reassigned after it has been initialized). Whereas, var declares a mutable variable (i.e., a variable that can be reassigned). The following example shows their usage. val x = 10 // x is a val x = 20 // This will result var variables are often used for storing values that can change over the course of a program's execution, such as counters, loop variables, or user input. Differences Between Val And Var. The main difference between val and var is that val variables are immutable, while var variables are mutable. This has important implications for how we write Thus, variables declared using let minimize the possibilities of runtime errors, as the compiler give compile-time errors. This increases the code readability and maintainability. Const. Variables can be declared using const similar to var or let declarations. The const makes a variable a constant where its value cannot be changed. Adding const modifier to the val keyword creates a compile-time constant, which means the value has to be known at the compile time. Because of these constraints, const val has below restrictions. It is only allowed to initialize const val with String or primitive types. In the above example, assigning Mutable (10) object to the const val will For example, an integer can not be assigned to a long variable. This does not compile: val x: Int = 20 val y: Long = x. You need to do an explicit casting: val x: Int = 20 val y: Long = x.toLong() Conclusion. These are some of the most outstanding differences you can find between variables in Java and Kotlin. .

difference between var and val