What Are The Differences Between Java And Python Variables Declaration?

Answer 1

You cannot declare a variable in Python without assigning some value to it. This is simply because a variable's type is inferred from the type of value that you assign to it.

a = "hello world" # a is a string

b = 42 # b is an integer

c = 3.14 # c is a float

d = [4, 8, 15, 16, 23, 42] # d is an integer array

In Java, all variable declarations must explicitly include a type even when declared with an initial value. The initial value, when given, must be of the same type or of a type that is covariant with the variable's type.

String a = "hello world";

int b = 42;

double c = 3.14

int[] d = {4, 8, 15, 16, 23, 42}

Note that local variables in Java that are declared but not assigned a value are considered "uninitialised". You must assign a value to all local variables before using them. Instance variables (members of a class) are always initialised. That is; numeric types have an initial value of zero, Boolean types are false and object references are null.