FreeNotes
Dynamic memory allocation allows programs to allocate memory at runtime, enabling flexibility in managing memory. This is achieved through functions like malloc(), calloc(), and free(). malloc(): The malloc() function allocates a block of memory of a specified size and returns a pointer to it. The memory is not initialized. int *ptr = (int *)malloc(5 * … Read more
In C, a function is a self-contained block of code that performs a specific task. Functions are used to break down a program into smaller, reusable sections, making the code more organized and modular. The function is defined by its name, return type, parameters, and body. Functions in C can be categorized into two types: … Read more
C provides three primary types of loops to perform repetitive tasks: for, while, and do-while loops. For Loop: The for loop is used when the number of iterations is known beforehand. It has three parts: initialization, condition check, and increment/decrement. Example: for (int i = 0; i < 5; i++) { printf(“%d “, i); } … Read more
In C, = is the assignment operator, used to assign a value to a variable. For example, x = 5; assigns the value 5 to the variable x. On the other hand, == is the equality operator, used to compare two values for equality. It returns true (1) if the values are equal, and false … Read more
A switch statement is a control flow mechanism in C used to execute one of many code blocks based on the value of a variable. It evaluates an expression and compares its value with multiple case labels. When a match is found, the corresponding block of code is executed. The break statement is used to … Read more
In C, storage classes define the scope, lifetime, and visibility of variables. The main types are: auto: Default for local variables, their scope is limited to the block in which they are declared. register: Used for variables that should be stored in a register rather than RAM for faster access. static: Preserves the value of … Read more
Both while and do-while are used for repeating a block of code, but they differ in how they check the loop condition. In a while loop, the condition is checked before the code block is executed, meaning the loop may not execute at all if the condition is false initially. In contrast, a do-while loop … Read more
A pointer in C is a variable that stores the memory address of another variable. Instead of holding data itself, a pointer holds the location where the data is stored in memory. Pointers are used to directly access and modify the value of variables through their addresses. To declare a pointer, the asterisk (*) symbol … Read more
A preprocessor directive in C is a special instruction to the C compiler that is processed before the actual compilation begins. Preprocessor directives are processed by the preprocessor, a tool that runs before the C compiler starts its job. These directives begin with a hash symbol (#) and are used to handle various tasks such … Read more
In C, variables are used to store data, and their names must follow specific rules to ensure consistency, clarity, and functionality. Here are the primary rules for naming variables in C: Alphanumeric Characters and Underscores: Variable names can consist of letters (both uppercase and lowercase), digits, and underscores (_). However, they cannot start with a … Read more