What is difference between static and constant variable in java?
Static variables are common across all instances of a type. constant variables are specific to each individual instance of a type but their values are known and fixed at compile time and it cannot be changed at runtime.
What is the difference between static and dynamic variable in java?
In short static variables memory is shared among all objects of class and can be modified. Dynamic variable means you want to create variable of class dynamic which is not possible instead of this you can initialize variable on dynamic using java reflection. All variables are dynamic unless you make them final .
What is the difference between static and external variables?
static means a variable will be globally known only in this file. extern means a global variable defined in another file will also be known in this file, and is also used for accessing functions defined in other files. A local variable defined in a function can also be declared as static .
What is the difference between static and automatic variables?
Automatic variables create a new each time when program’s execution enters in the function and destroys when leaves. Static variable create once, when program’s execution enters in the function first time, destroys when program’s execution finishes, they do not again.
What is constant variable in Java?
A constant is a variable whose value cannot change once it has been assigned. Java doesn’t have built-in support for constants. A constant can make our program more easily read and understood by others. … To define a variable as a constant, we just need to add the keyword “final” in front of the variable declaration.
When should I use static variables?
When you want to have a variable that always has the same value for every object of the class, forever and ever, make it static . If you have a method that does not use any instance variables or instance methods, you should probably make it static .
What is static and dynamic RAM?
SRAM (static RAM) is random access memory (RAM) that retains data bits in its memory as long as power is being supplied. Unlike dynamic RAM (DRAM), which stores bits in cells consisting of a capacitor and a transistor, SRAM does not have to be periodically refreshed.
Can we use extern and static keywords together?
Static variables. … Thus, prefixes “ extern ” and “ static ” cannot be used in the same declaration. They maintain their value throughout the execution of the program independently of the scope in which they are defined.
What functions are a static variable visible to?
What functions are a static variable visible to? Calrification: The static keyword makes the variable only visible to one function. The data held by static variables is not erased when the function call is over.
How does a static variable work?
Static Variables: When a variable is declared as static, then a single copy of the variable is created and shared among all objects at a class level. Static variables are, essentially, global variables. All instances of the class share the same static variable.