Please explain me Pass by value and pass by reference

Question

What is use of these

Answer 1

The terms “pass by value” and “pass by reference” are used to describe how variables are passed on. To make it short: pass by value means the actual value is passed on. Pass by reference means a number (called an address) is passed on which defines where the value is stored.

https://blog.penjee.com/passing-by-value-vs-by-reference-java-graphical/

https://www.educative.io/edpresso/pass-by-value-vs-pass-by-reference

https://pediaa.com/what-is-the-difference-between-pass-by-value-and-pass-by-reference/amp/

https://stackoverflow.com/questions/373419/whats-the-difference-between-passing-by-reference-vs-passing-by-value

https://courses.washington.edu/css342/zander/css332/passby.html

Answer 2

When you're passing by value the CPU copies the value and uses it somewhere else.. for example in a function. When you change this value in the specific function and the function ends, nothing will be changed.

On the other hand if you pass the variable by a reference the CPU will get physical address of that variable and changing its value in function will change the variable even in the place where you were calling that function.