A structure in C is a user-defined type that groups related variables of different types under one name. Where an array holds many values of the same type, a struct holds a fixed set of named fields — each with its own type. This is what makes it possible to represent a student record, a …
A pointer is a variable that holds a memory address. This single idea — that a variable can store where data lives rather than the data itself — is what makes C capable of things most languages cannot do cleanly: passing large structures without copying them, building linked lists and trees, writing to hardware registers …
The C standard library provides a complete set of string functions in <string.h>. Unlike higher-level languages, C strings are just null-terminated arrays of char — there is no built-in string type, so these functions do the work that other languages bake into the runtime. This guide covers every function you will use regularly, with a …
The C Programming Quiz app is now live on Google Play. If you have been practicing C on this site — working through examples, solving K&R exercises, or studying for interviews — this app is the natural next step: over 150 multiple-choice questions you can run through anywhere, with no internet connection required. Download C …
An interrupt is a hardware signal that suspends the CPU’s current execution, saves the processor state, runs a dedicated function called an Interrupt Service Routine (ISR), then restores the state and resumes where it left off. Interrupts let embedded firmware react to events — a byte arriving on UART, a button press, a timer expiry …
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