Technical Interview Questions and Answers :: Virtusa
Tot. Mock Test: 3
Total Qs: 209+
To delete the data permanently we use 'commit' statement, to roll the transaction back to a certain point, without rolling back the entire transaction we use 'savepoint', to get deleted data rollback is used.
Procedure are used as a script
function are used as a method
procedure can returned zero , single or multiple values
function can returned one value which is mandatory
procedure have input/output parameters
function have input parameter only
procedure can not be used in select statement
function can be used in a select statement
USED TO CONVERT HIERACHICAL STRUCTURE TO THE FLAT STRUCTURE. IT IS USED TO JOIN A TABLE ITSELF AS LIKE IF THAT IS THE SECOND TABLE
View created with base table, force view created without base table..
arrays store only primitive type values and arraylist store primitive type
An exception is a problem that arisesduring excecution. Checked exceptions are the exceptions that gets checked at the compile time. Unchecked exceptions are not checked at compile time, in Java all exceptions are unchecked exceptions.
For numbers primitive data types are used normally, such as byte, int, long, double etc. But in programming, objects are sometimes required rather than primitive data types. For this, wrapper classes are available in Java.
1) Encapsulation: It is the mechanism that binds together code and data in manipulates, and keeps both safe from outside interference and misuse. In short it isolates a particular code and data from all other codes and data. A well-defined interface controls the access to that particular code and data.
2) Inheritance: It is the process by which one object acquires the properties of another object. This supports the hierarchical classification. Without the use of hierarchies, each object would need to define all its characteristics explicitly. However, by use of inheritance, an object need only define those qualities that make it unique within its class. It can inherit its general attributes from its parent. A new sub-class inherits all of the attributes of all of its ancestors.
3) Polymorphism: It is a feature that allows one interface to be used for general class of actions. The specific action is determined by the exact nature of the situation. In general polymorphism means "one interface, multiple methods"; this means that it is possible to design a generic interface to a group of related activities. This helps reduce complexity by allowing the same interface to be used to specify a general class of action. It is the compiler's job to select the specific action (that is, method) as it applies to each situation.
Container class is a class that hold group of same or mixed objects in memory. It can be heterogeneous and homogeneous. Heterogeneous container class can hold mixed objects in memory whereas when it is holding same objects, it is called as homogeneous container class.
A token is the smallest element of a C program that is meaningful to the compiler. The C parser recognizes these kinds of tokens: identifiers, keywords, literals, operators, punctuators, and other separators. A stream of these tokens makes up a translation unit.