L&T Technology Services Software Engineer Interview Questions and Answers

Technical questions related to programming concepts and recursion

• Pointers are variables that store the memory address of another variable

• Functions are blocks of code that perform a specific task

• OOPS is a programming paradigm that uses objects to represent real-world entities

• Factorial using recursion: int factorial(int n) { if(n==0) return 1; else return n*factorial(n-1); }

DBMS keys are used to uniquely identify a record in a table. Primary, foreign, candidate, and super keys are some of the types.

• Primary key: uniquely identifies a record in a table

• Foreign key: links two tables together

• Candidate key: can be used as a primary key

• Super key: a set of attributes that can uniquely identify a record

• Composite key: a combination of two or more attributes used as a primary key

A null pointer is a pointer that does not point to any memory location.

• Null pointers are used to represent that a pointer does not point to a valid object or memory location.

• Attempting to dereference a null pointer can result in a segmentation fault or program crash.

• Null pointers are commonly used in programming languages like C and C++.

• Example: int* ptr = nullptr; // ptr is a null pointer

Overloading is having multiple methods with the same name but different parameters. Overriding is implementing a method in a subclass that is already defined in the parent class.

• Overloading: Same method name with different parameters (e.g. sum(int a, int b) and sum(int a, int b, int c))

• Overriding: Subclass method overrides superclass method (e.g. Animal class with makeSound() method, Cat subclass with makeSound() method)

• Overloading is resolved at compile time while overriding...read more

malloc is a function in C programming used to dynamically allocate memory during runtime.

• malloc stands for 'memory allocation'.

• It is used to allocate a specific amount of memory during program execution.

• The allocated memory is not automatically initialized and must be manually managed.

• Example: int *ptr = (int*) malloc(5 * sizeof(int));

Free refers to something that is given or available without cost or payment.

• Free products or services do not require any payment.

• Free can also refer to freedom or liberty, such as free speech or free will.

• Free can also mean available for use without restrictions, like open-source software.