C Programming: A Beginner's Glossary

 

Welcome to the world of C programming! Building a solid vocabulary is the first step toward mastering any new language, and C is no exception. This glossary provides simple, clear definitions for essential terms you'll encounter. Use this guide to help you build a strong foundation for your coding journey.

1. C

• calloc(): A dynamic memory allocation function.
• Call by reference: In 'Call by reference', the memory address of a variable is passed to a function, rather than its value.
  • The function receives a reference (the address) to the original variable.
  • The function can directly alter the value of the original variable.

2. D

• Data Types: The four categories of data types in the C programming language.
  • Basic data types
    • Arithmetic data types, further divided into integer and floating-point types
  • Enumerated data types
    • Arithmetic data types that define variables and assign discrete integer values only
  • Void data types
    • No value is available
  • Derived datatypes
    • Array types, pointer types, function, structure and union types

3. E

• Entry Controlled Loop: A loop where the condition is checked before the loop body is executed. The For loop is an example of this, and its defining characteristic is that the condition is checked at the beginning of the loop.
• Exit Controlled Loop: A loop where the condition is checked after the loop body has been executed. The do-while loop is an example. Its defining characteristic is that the condition is checked at the end, which guarantees the loop runs at least once.
• == (Equal To Operator): A relational operator, also known as the "equivalent to" or "equal to" operator. It is used to compare two values or variables.

4. F

• fseek(): A function used to set the file position indicator for a file that has been opened by fopen(). It requires three parameters to work:
  1. The number of bytes to search
  2. The point of origin of the file
  3. A file pointer to the file
• free(): A function used to release a block of memory that was previously allocated. Memory can also be released by using the alternative method realloc(ptr,0).

5. H

• Header file inclusion (""): When a header file is included using double quotes (e.g., #include "myfile.h"), the compiler begins a two-step search process. It first searches in the compiler's current working directory. If the file is not found there, it then searches the built-in include path.
• Huge Pointers: A 32-bit pointer. Its key capability is that, unlike a far pointer, it can access memory outside its segment, and its segment part can be modified.

6. I

• #include: A statement processed by the pre-processor software before the code is compiled. Using #include increases the size of the final code.
• int (reserved word): The word int is considered a reserved word because it is part of the standard C language library. This status means it is not possible to use it for any other activity except its intended functionality (defining an integer data type).

7. M

• Modifier: A prefix used with primary data types to indicate a modification of the storage space allocation for a variable. The five available modifiers are:
  1. short
  2. long
  3. long long
  4. signed
  5. unsigned

8. P

• Pointers: When a pointer *a points to a variable v, the variable v might contain either the address of another memory location or a value.
• Prototype Function: A declaration that informs the compiler about a function that will be defined later. It provides the compiler with three key pieces of information:
  • Name of the function
  • Parameters list of the function
  • Return type of the function

9. S

• s++ and ++s: Operators used to increment the value of a variable s by one.

Operator	Description
s++	Post increment: Increments the value of s by 1 after the current expression is evaluated.
++s	Pre-increment: Increments the value of s by 1 before the current expression is evaluated.

• sscanf(): The statement sscanf(str, "%d", &i); is used to convert a string value to an integer value.
• <stdio.h>: A header file that contains prototypes and definitions for standard input and output commands, such as scanf and printf.
• Stack Area: A region of memory used to store arguments and local variables of a method. It remains in memory only until the particular method is terminated.
• static functions: Functions declared with the static keyword, primarily to restrict access to them.
  • This restriction prevents functions in other files from accessing them.
  • It allows for the reuse of the same function name in multiple files without conflict.

10. T

• Ternary Operator: The conditional operator in C, represented by the symbol ?:.

11. U

• Union: A special data type used to store different types of data in the same memory location.

12. V

• volatile: A keyword used to declare objects that should be omitted from compiler optimization. This is done because, at any time, the values of these objects can be changed by code that is outside the scope of the current code.

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Mastering this core vocabulary is a crucial first step on your path to becoming a proficient C programmer.

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