C Keywords: The Foundation of Programming Excellence

int

The 'int' keyword is used to declare integer-type variables, which can hold whole numbers like 3, -1024, or 456789.

char

The 'char' keyword is used to declare character type variables, capable of holding ASCII characters or small integer values.

float

The 'float' keyword is used to declare single-precision floating-point variables. These variables can hold real numbers, such as 3.14, -0.005, or -8.3778e12.

double

The 'double' keyword is used to declare a double precision floating point variable, capable of holding very large (or small) numbers with a high degree of precision.

short

The 'short' keyword is a modifier that can be applied to integer types, reducing their size and, consequently, the range of values they can store.

long

The 'long' keyword is used as a modifier to integer types, allowing them to hold larger numbers than they would otherwise be able to store. This is particularly useful when dealing with values that may exceed the range of standard integer types.

signed

The 'signed' keyword is used to declare a signed type. Signed integer types can represent both positive and negative values.

unsigned

The 'unsigned' keyword in C programming is used in conjunction with integer types to declare that the type can hold only non-negative numbers.

void

The 'void' keyword in C programming is used to declare functions without a return value or to declare generic pointers.

if

The 'if' keyword is used to create conditional statements. This allows the program to make decisions based on certain conditions, executing different blocks of code based on whether a condition is true or false.

else

The 'else' keyword is used in conditional statements to define a block of code that will be executed if the condition in an if statement is false.

do

The 'do' keyword is used in conjunction with 'while' to create a do-while loop that executes a block of code at least once, then repeats based on a condition evaluated at the end.

while

The 'while' keyword in C programming is used to implement while loops, which are used when a block of code needs to be executed repeatedly as long as a certain condition is true.

for

The 'for' keyword is used to implement "for" loops, which are used when a block of code needs to be executed a specific number of times. It compactly combines initialization, testing, and incrementing/decrementing in one line.

switch

The 'switch' keyword is used to create a switch statement, which allows multi-way branching based on the value of a variable or expression.

case

The 'case' keyword is a fundamental part of switch statements. It’s used to label each potential output of a switch statement, followed by a value and a colon.

default

The 'default' keyword is used in switch statements to define the action to be taken if no case matches the evaluated expression.

break

The 'break' keyword is employed within loops or switch statements to terminate the current loop or switch statement and resume execution at the next statement following it.

continue

The 'continue' keyword, when used within a loop, skips the remainder of the current iteration and moves directly to the next one.

goto

The 'goto' keyword is used to transfer control to the labeled statement. While it can be useful in some situations, misuse can lead to code that is difficult to understand and debug, so its use is generally discouraged.

auto

The 'auto' keyword is used to declare automatic variables, which are local in their nature. These variables are created when the block containing them is entered, and they're destroyed upon exit. However, this keyword is rarely used because local variables are auto by default

register

The 'register' keyword suggests that the variable be stored in a CPU register instead of RAM for faster access. However, the final decision is made by the compiler.

extern

The 'extern' keyword is used to declare an external variable or a variable that is visible to all program files when declared globally. It allows different files to share the same variable or function.

static

The 'static' keyword is used to declare static variables. Unlike regular variables, static variables retain their values between function calls.

struct

The 'struct' keyword is used to define a structure type, a user-defined data type that can hold different data types.

union

The 'union' keyword is used to define a union, a special data structure that allows storing different data types in the same memory space.

All the members of the union share the same memory space.

return

The 'return' keyword is used to return a value from a function back to the function call. If the function is of void type, return is used without a value to signal the end of the function.

sizeof

The 'sizeof' keyword is a compile-time operator used to determine the size, in bytes, of a data type or a variable.

const

With 'const', you can declare variables whose value cannot be changed after the initial assignment, making them read-only.

enum

The 'enum' keyword is used to declare an enumerated data type. It allows for a variable to be one of a few pre-defined constants, increasing code readability and reducing the chances of an invalid value being assigned.

typedef

The 'typedef' keyword is used to create an alias name for an existing data type. It's often used to simplify complex data type declarations.

volatile

The 'volatile' keyword in C programming is used to declare variables that can be changed in ways not explicitly defined by the program, such as by a hardware address or a different thread.