American Express Interview Questions and Answers

Memory allocation for class and instance creation in Java

• Memory is allocated for class variables and methods when the class is loaded into memory

• Memory for instance variables is allocated when an instance of the class is created

• The amount of memory allocated depends on the data type and size of the variables

• Static variables are allocated memory only once, while instance variables are allocated memory for each instance

• Memory allocation can be optimized using techniques like ob...read more

Distributed systems involve multiple computers working together, multitasking allows for multiple tasks to be performed simultaneously, Amazon uses distributed systems for their online services.

• Distributed systems involve multiple computers working together to achieve a common goal

• Multitasking allows for multiple tasks to be performed simultaneously by a single computer

• Multiprogramming allows multiple programs to run on a single computer at the same time

• Amazon uses distribute...read more

TCP header contains important information for reliable data transmission.

• TCP header includes source and destination port numbers

• It also includes sequence and acknowledgement numbers

• TCP header has flags for various control functions like SYN, ACK, FIN, etc.

• Window size, checksum, and urgent pointer are also included in TCP header

IPv6 offers more IP addresses, better security, and improved performance compared to IPv4.

• IPv6 uses 128-bit addresses, providing a virtually unlimited number of unique IP addresses.

• IPv6 includes built-in security features, such as IPsec, which provides end-to-end encryption and authentication.

• IPv6 also offers improved performance through features like multicast and anycast addressing.

• IPv6 simplifies network configuration and management through auto-configuration and plug-and-...read more

Merge two sorted arrays into a single sorted array

• Create a new array to store the merged result

• Use two pointers to iterate through both arrays and compare elements

• Add the smaller element to the new array and move the pointer for that array