American Express Technical Analyst Interview Questions and Answers

Var is a keyword in programming languages used to declare variables.

• Var is short for variable.

• It is used to declare a variable and assign a value to it.

• The data type of the variable is inferred from the assigned value.

• Example: var x = 5; // x is now a variable of type integer with value 5

To make a class immutable, we need to ensure that its state cannot be modified after creation.

• Make all fields private and final

• Do not provide any setters

• If mutable objects are used, return copies instead of references

• Ensure that any methods that modify state return a new instance instead of modifying the existing one

Threads are lightweight processes that share memory and resources, while processes are independent and have their own memory and resources.

• Threads are a part of a process and share the same memory space.

• Processes are independent and have their own memory space.

• Threads are faster to create and switch between than processes.

• Processes are more secure and stable than threads.

• Examples of processes include web browsers and t...read more