C Programming Questions For Practice
C is a high-level structured programming language. It was developed by Dennis Ritchie at Bell Labs as a system programming language for re-implementing the UNIX operating system.
Some of the key features of C are portability, modularity, and extensibility. These features make C a popular programming language. Hence, there are many companies looking for C professionals.
Basics
The basics of C programming are important to understand if you want to become a better programmer. They include the use of variables, their effects on programming, and basic programming ideas that can be applied to most popular languages.
Variables are a crucial part of C programs, as they allow the program to hold data that can be easily accessed. They also help to make it easier for developers to add new functionality and update existing code without having to change everything.
C variables are like numbers, and their values can be changed by the programmer. The value of a variable is stored in a memory location that is identified by the variable’s name.
A variable’s name can begin with a letter or an underscore, and can contain letters, numbers, and other special characters. However, it should never start with a number and must be unique.
In addition to being used to store data, variables are also useful for checking and verifying values. For example, you can use the equals operator to check if two variables are the same.
Another type of variable is the constant, which refers to a fixed value that the programmer can access at any time. These can be useful in programs that require a large amount of memory.
C is a statically-typed language, meaning that each variable has its own type and is known at compile time. This is different from most other languages, which rely on an interpreter to determine the type of variables. This can be confusing for novice programmers, but it’s an important aspect of C that helps it to be highly optimized.
Variables
Variables are storage locations in a program that allow data to be changed and reused during execution. They represent data like booleans, names, integers, arrays, pictures, sounds, scalars, and strings.
A variable in C is a unique name assigned to a storage location, which holds a value that can be changed and reused by other variables during execution. The symbolic names of variables are replaced with the actual data location by compilers and interpreters during the course of a program’s execution.
The type of a variable determines the size and layout of its memory; the range of values it can store; and the set of operations it can perform. In C, there are four types of variables: integers, floats, doubles, and floating point numbers.
There are also external variables, which share the same values across multiple C files. These are declared by using the extern keyword.
These are global variables, which can be accessed by any function. However, you should be careful when using them because they can increase the inter-component coupling surface in your code.
They can also be easily misused, which can lead to errors and bugs in your code. As a general rule, if you can find a more efficient way to do something, don’t use a global variable.
Data types
Data types are a very important concept to understand in C programming. Each type of data has a different effect on your programming. Hence, it is important to know them thoroughly before beginning any program in C.
The primary data types in C are int, char, float, and double. Each one of these differs in size and range from the other.
Ints, for example, are usually of 2 bytes. However, they can be of 4 bytes or even 8 bytes. The length of these values is determined by the compiler.
Floats are similar to ints but they can have a higher precision. Unlike ints, you can have up to 10 digits after the decimal place with floats.
Another important data type in C is boolean, which can have only two values: True or False. Often, you’ll encounter this data type when writing a logic circuit.
In addition to the fundamental data types, there are also derived and user-defined data types. Derived data types allow you to combine basic data types to store multiple values in a single variable.
Likewise, a structure is a group of data-type elements that can be stored in the same memory location. In C, you can define a structure using the’struct’ keyword.
Loops
Loops are a very important aspect of programming and are incredibly useful for dealing with repetitive tasks. This is one of the most common reasons that people learn to program in the first place — being able to repeatedly execute code over and over again is one of the most basic yet fundamental things that can be done with programming.
To start with, we need to understand why these loops are so important in the first place. The most obvious reason is that they can be used to repeatedly execute code for a set number of times (as in the example below).
Another advantage of these loops is that they can be nested, which makes them even more powerful and convenient. This means that you can define more than one loop within a loop, and the program will execute these within a specific order.
Choosing the correct loop type is important, however, as it can make all the difference in how the program works. A for loop is generally more intuitive than a while loop, but both types are essentially interchangeable, so they’re all worth learning.
A while loop is similar to a for loop but it contains a condition that is checked every time the loop iterates. The condition determines when the loop should stop iterating, and when that happens, the control is automatically returned to the next line of code within the while loop.
Functions
Functions are a great way to organize a program. They can break a long program into logical parts that make sense when read, and they can be easily rewritten.
Functions also reduce the complexity of a program and optimize it for performance. The C standard library contains numerous built-in functions that your program can call, such as strcat() to concatenate two strings or memcpy() to copy a memory location to another.
A function definition includes three main parts: a function header, the argument declaration, and the function body. The function header tells the compiler about the name of the function, its number of parameters, data types of parameters, and return type. The function body is the actual code for the function.
Arguments are used to pass information from the calling portion of the program to the function. They can be a single value or several values. When a function is called, the value passed to the function is returned to the calling program via a return statement.
Each formal argument must be declared at this point in the function. They must have the same data type as the corresponding actual arguments in the calling function. This allows the information to be transferred between them without changes made to the actual argument being affected by the changes in the formal parameter. Similarly, each actual argument must be written in the same order and with the same identifiers as their corresponding formal arguments.
Statements
Statements are syntactic units that specify the actions to be performed by a program. They are generally written with a syntax that is determined by the programming language in which they are written.
Statements can contain expressions, which are any combination of keywords, identifiers, constants, variables, property names, array elements, and function calls. They can also include other syntax elements that affect the appearance and meaning of statements, such as brackets, parentheses, and commas.
Some statements can also contain comments, which are added to the body of a statement. To add a comment, insert an apostrophe (‘) or REM after the statement, followed by a space.
Conditional statements are used to decide whether to execute a block of code, based on a single or multiple conditions. They are used in the same way as if statements, but they can be more complex.
The if statement is the most basic type of conditional statement in C programming. The if statement consists of a Boolean expression that evaluates to true or false. If the expression evaluates to true, then the body of the if statement will be executed. If it evaluates to false, then the body of the if statement is not executed.