Introduction
C is the ancestor of almost every language you will meet in a government IT exam — C++, Java, C#, JavaScript and Python all borrow its syntax and ideas. It is a compiled, statically-typed, procedural language that sits very close to the hardware: it gives you direct access to memory through pointers. Because of this closeness, C questions test whether you truly understand how a program stores data, calls functions and manages memory — not just whether you can memorise syntax.
For BCS, Bank IT, and IT-officer written and MCQ papers, C appears in two ways: (1) short conceptual MCQs (data types, operators, storage classes, sizeof, format specifiers), and (2) "predict the output" or "spot the error" questions that almost always revolve around pointers, arrays and pass-by-value/pass-by-reference. Master pointers and you master the hardest 40% of the paper.
Learning objectives
- Describe the structure of a minimal C program and the compilation pipeline.
- Use the fundamental data types, know their typical sizes, and read/write with correct format specifiers.
- Apply operators with correct precedence and associativity, including the tricky
++/--,&,*,%, and ternary operators. - Explain what a pointer is, declare and dereference it, and reason about pointer arithmetic.
- Explain the deep relationship between arrays and pointers, including why
a[i] == *(a + i). - Distinguish pass-by-value from pass-by-reference (via pointers) and predict function output.
- Understand strings as
chararrays, and the four storage classes (auto,register,static,extern). - Avoid the classic bugs: dangling pointers, memory leaks, off-by-one, and
=vs==.