**Course Title:** Mastering C: From Fundamentals to Advanced Programming **Section Title:** Introduction to C and Development Environment **Topic:** Basic C syntax: Variables, data types, and operators In the previous topics, we explored the history and evolution of the C programming language and set up a development environment to start coding. In this topic, we will delve into the fundamental syntax of C programming and explore variables, data types, and operators. ### Variables in C Variables are names given to a location in memory that holds a value. In C, variables are declared before they can be used, and each variable has a specific data type that determines its size and behavior. **Declaring Variables** A variable is declared by specifying its data type followed by its name. Here is a simple example: ```c int myVariable; ``` In this example, `myVariable` is the name of the variable, and `int` is its data type. ### Data Types in C C has several built-in data types that are used to store different types of values. Here are some of the most common data types: | Data Type | Description | Size (bytes) | Example | |-----------|-------------------|-------------|---------| | `int` | Integer value | 2 or 4 | 1, 2, 3 | | `float` | Floating-point | 4 | 3.14, -0.5 | | `char` | Character | 1 | 'a', 'z' | | `double` | Double-precision | 8 | 0.000001 | | `bool` | Boolean value | 1 | true, false | Note: The size of a data type may vary depending on the system architecture. **Initializing Variables** Variables can be initialized at the time of declaration or later in the code. ```c // Initializing a variable at declaration int myVariable = 10; // Initializing a variable later int myVariable; myVariable = 10; ``` ### Operators in C Operators are used to perform operations on variables and values. C provides various types of operators: 1. **Arithmetic Operators** | Operator | Description | Example | |----------|-------------|---------| | `+` | Addition | `a + b` | | `-` | Subtraction | `a - b` | | `*` | Multiplication | `a * b` | | `/` | Division | `a / b` | | `%` | Modulus | `a % b` | 2. **Assignment Operators** | Operator | Description | Example | |----------|-------------|---------| | `=` | Assign | `a = b` | | `+=` | Add and Assign | `a += b` | | `-=` | Subtract and Assign | `a -= b` | | `*=` | Multiply and Assign | `a *= b` | | `/=` | Divide and Assign | `a /= b` | | `%=` | Modulus and Assign | `a %= b` | 3. **Comparison Operators** | Operator | Description | Example | |----------|-------------|---------| | `==` | Equal to | `a == b` | | `!=` | Not Equal to | `a != b` | | `>` | Greater than | `a > b` | | `<` | Less than | `a < b` | | `>=` | Greater than or Equal to | `a >= b` | | `<=` | Less than or Equal to | `a <= b` | **Practical Example** ```c #include <stdio.h> int main() { // Declare and initialize variables int a = 10; int b = 20; // Perform arithmetic operations int sum = a + b; int difference = a - b; // Use comparison operator if (a > b) { printf("a is greater than b\n"); } else { printf("a is less than or equal to b\n"); } // Print results printf("Sum: %d\n", sum); printf("Difference: %d\n", difference); return 0; } ``` **Key Takeaways** * Variables are declared before they can be used and must have a specific data type. * C has several built-in data types, including `int`, `float`, `char`, `double`, and `bool`. * Operators are used to perform operations on variables and values. * Arithmetic operators perform mathematical operations. * Assignment operators assign values to variables. * Comparison operators compare values. **What to Expect Next** In the next topic, 'Writing your first C program: Hello, World!', we will put our knowledge of basic C syntax into practice by writing and executing our first C program.