10+ Ericsson Software Developer Interview Questions and Answers

Reverse a given string containing alphabets, numbers, and special characters.

• Iterate through the string from the end to the beginning and append each character to a new string.

• Use built-in functions like reverse() or StringBuilder in languages like Python or Java for efficient reversal.

• Handle special characters and numbers while reversing the string.

• Ensure to consider the constraints on the length of the string and the number of test cases.

Use the COUNT DISTINCT function in SQL to find the number of unique values in a database.

• Use the COUNT DISTINCT function along with the column name to count the number of unique values in that column.

• For example, SELECT COUNT(DISTINCT column_name) FROM table_name;

• You can also use GROUP BY to find the number of unique values for multiple columns.

Process life cycle in an operating system involves creation, execution, termination, and resource management.

• Creation: When a process is created, it is assigned a unique process ID and allocated necessary resources.

• Execution: The process is then scheduled by the operating system to run on the CPU.

• Termination: Once the process completes its task or is terminated by the user, it is removed from memory.

• Resource Management: The operating system manages resources such as CPU time,...read more

A hub operates at the physical layer and broadcasts data to all devices on the network, while a switch operates at the data link layer and forwards data only to the intended recipient.

• Hub operates at the physical layer, while switch operates at the data link layer

• Hub broadcasts data to all devices on the network, while switch forwards data only to the intended recipient

• Switch is more efficient and secure compared to a hub

Multiprocessing involves multiple processors executing multiple tasks simultaneously, while multiprogramming involves multiple programs sharing a single processor by switching between them.

• Multiprocessing utilizes multiple processors to execute multiple tasks concurrently.

• Multiprogramming involves multiple programs sharing a single processor by switching between them.

• Multiprocessing is more efficient in terms of performance as tasks can run simultaneously on different process...read more

Windows XP and Windows 7 are both operating systems developed by Microsoft, but they have several key differences.

• User interface: Windows 7 has a more modern and user-friendly interface compared to Windows XP.

• Performance: Windows 7 is generally faster and more stable than Windows XP.

• Security: Windows 7 has more advanced security features and updates compared to Windows XP.

• Hardware support: Windows 7 supports newer hardware and technologies better than Windows XP.

• Compatibility...read more

An Object-Oriented Database Management System (OODBMS) is a type of database management system that supports the creation and management of objects in a database.

• OODBMS stores data in the form of objects, which can contain attributes and methods.

• It allows for complex data structures and relationships to be represented more easily.

• Examples of OODBMS include db4o, ObjectDB, and ObjectStore.

Different protocols supported at each OSI layer

• Layer 1 (Physical): Ethernet, Wi-Fi, Bluetooth

• Layer 2 (Data Link): MAC, PPP, HDLC

• Layer 3 (Network): IP, ICMP, ARP

• Layer 4 (Transport): TCP, UDP, SCTP

• Layer 5 (Session): NetBIOS, PPTP

• Layer 6 (Presentation): SSL, TLS

• Layer 7 (Application): HTTP, FTP, SMTP

The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven different layers.

• Physical Layer: Deals with the physical connection between devices. Example: Ethernet cables.

• Data Link Layer: Responsible for node-to-node communication. Example: MAC addresses.

• Network Layer: Manages routing of data packets. Example: IP addresses.

• Transport Layer: Ensures end-to-end communication. Example:...read more

RDBMS is a type of DBMS that stores data in a structured format with relationships between tables.

• RDBMS enforces referential integrity and allows for normalization of data.

• DBMS is a general term for any system that manages databases, while RDBMS specifically refers to relational databases.

• Examples of RDBMS include MySQL, Oracle, and SQL Server.

• Examples of DBMS include MongoDB and Redis.

A deadlock is a situation in which two or more processes are unable to proceed because each is waiting for the other to release a resource.

• Occurs in multitasking environments where processes compete for limited resources

• Can be resolved using techniques like deadlock prevention, deadlock avoidance, and deadlock detection

• Example: Process A holds Resource X and waits for Resource Y, while Process B holds Resource Y and waits for Resource X

Method overloading is when multiple methods have the same name but different parameters. Method overriding is when a subclass provides a specific implementation of a method that is already provided by its superclass.

• Method overloading allows a class to have multiple methods with the same name but different parameters.

• Method overriding occurs in a subclass when a method has the same name, return type, and parameters as a method in its superclass.

• Example of method overloading: ...read more

A thread is a lightweight sub-process that allows concurrent execution within a single process.

• Threads share the same memory space within a process.

• Threads are used to achieve parallelism and improve performance.

• Examples of threads include the main thread in a program and worker threads in a multi-threaded application.

Swapping two variables without using a third variable

• Use XOR operation to swap two variables without using a third variable

• Example: a = 5, b = 10; a = a ^ b; b = a ^ b; a = a ^ b; // Now a = 10, b = 5

3G, 4G, and 5G architectures refer to the generations of mobile network technology, each offering faster speeds and improved capabilities.

• 3G (Third Generation) introduced mobile data services like internet browsing and video calling.

• 4G (Fourth Generation) provided faster speeds for data transmission, enabling services like HD video streaming and online gaming.

• 5G (Fifth Generation) offers even faster speeds, lower latency, and increased capacity for more connected devices, ena...read more