UST Mainframe Operator Interview Questions and Answers

Job Control Language (JCL) is used to define and execute jobs on mainframe systems.

• JCL statements are used to specify the job to be executed, including input/output files, program to be run, and other job control parameters.

• Example: //JOBNAME JOB (ACCOUNT), 'DESCRIPTION',CLASS=A,MSGCLASS=X

• JCL statements are written in a specific format with keywords and parameters to define the job steps and execution flow.

• Example: //S

IDCAMS is the utility used to create a GDG.

• IDCAMS is a utility program used in z/OS to define and manage VSAM datasets, including GDGs (Generation Data Groups).

• To create a GDG using IDCAMS, you would typically write a JCL job that includes IDCAMS statements to define the GDG base and generations.

• Example: //STEP1 EXEC PGM=IDCAMS //SYSIN DD * DEFINE GDG(NAME(TEST.GDG) LIMIT(10) SCRATCH)

Call by value passes a copy of the value while call by reference passes the address of the value.

• Call by value is used for simple data types like int, float, etc.

• Call by reference is used for complex data types like arrays, structures, etc.

• Call by value does not modify the original value while call by reference can modify the original value.

• Call by value is faster than call by reference as it does not involve memory ac...read more

OOPs is a programming paradigm based on the concept of objects that interact with each other.

• OOPs stands for Object-Oriented Programming.

• It focuses on creating objects that have properties and methods.

• Encapsulation, Inheritance, Polymorphism, and Abstraction are the four main pillars of OOPs.

• Example: A car is an object that has properties like color, model, and methods like start, stop, and accelerate.