Type Conversion

Type Conversion

  • Type conversion, also known as type casting, is the process of converting the value of one data type to another.
  • This is often necessary in programming when working with different data types, such as converting an integer to a string or a floating-point number to an integer.
  • There are two main types of type conversion:

Implicit Conversion (also known as automatic or coercion)

Explicit Conversion (also known as casting)

  • It can also lead to errors or loss of data if not done carefully.
  • Type conversion can be useful in various situations, such as:
    1. Data processing: converting data from one format to another for processing or analysis.
    2. User input: converting user input from a string to a numerical value for calculations.
    3. Data storage: converting data from one format to another for storage in a database or file.

Implicit Type Conversion:

  • It is also known as implicit casting.
  • Implicit conversion happens automatically when the compiler converts one data type to another.
  • For example, assigning an integer value to a floating-point variable.
  • This usually happens when you mix different data types in an expression or pass arguments to a function.

Todo: Convert the below image to a to our own personalized image. and also, add notes around it.

#include <iostream>  

using namespace std;  

int main()  
{  

  bool b = false;   
  char ch = 'o';  
  int i = ch;   
  cout << i << endl;  
  
  return 0; 
}   


The output of the program will be:  
111

Here’s a breakdown of what the code does:

  1. bool b = false; declares a boolean variable b and initializes it to false. (This variable is not used in the program.)
  2. char ch = ‘o’; declares a character variable ch and initializes it to the character ‘o’.
  3. int i = ch; declares an integer variable i and initializes it to the value of ch. Since ch is a character, its ASCII value is assigned to i. The ASCII value of ‘o’ is 111, so i will be assigned the value 111.
  4. cout << i << endl; The statement prints the value of i (which is 111) to the console, followed by a newline character.
  5. return 0; indicates successful execution of the program.

Explicit Type Conversion

  • Explicit conversion is also known as explicit casting or type casting.
  • It is a process in programming where a value of one data type is consciously converted to another data type using a casting operator or a conversion function.
  • Explicit conversion is when you explicitly specify the type of conversion using casting operators.
  • The programmer specifies the conversion using casting operators. It provides more control but requires careful handling to avoid errors.
#include <iostream>

using namespace std;

int main() 
{
  float a = 10;
  int i = 10;
  int j = 3;
  a = (float)10/3;
  cout << a << endl;
  return 0; 
}


The output of the program will be:

3.33333

Here’s a breakdown of what the code does:

  1. float a = 10; declares a floating-point variable a and initializes it to 10.0.
  2. int i = 10; declares an integer variable i and initializes it to 10. (This variable is not used in the program.)
  3. int j = 3; declares an integer variable j and initializes it to 3. (This variable is not used in the program.)
  4. a = (float)10/3; assigns the result of the division of 10 by 3 to a. The (float) cast ensures that the division is performed in floating-point arithmetic, and the result is assigned to a. Since the division is performed in floating-point, the result will be 3.333.
  5. The statement cout << a << endl prints the value of a (which is approximately 3.333…) to the console, followed by a newline character.

Benefits of using type conversion

  1. Data flexibility: Type conversion allows you to use data in different contexts, enabling flexibility in programming.
  2. Prevents errors: Explicit type conversion helps prevent implicit conversion errors, ensuring data integrity and accuracy.
  3. Improves code readability: By explicitly converting types, your code becomes more readable and self-explanatory.
  4. Type safety: Type safety is a programming concept that ensures a program’s correctness and stability by preventing type-related errors at compile-time or runtime
  5. Enhances programmer control: Type conversion gives you control over data types, allowing you to dictate how data is interpreted and used.
  6. Better memory management: Type safety helps ensure that memory is allocated and deallocated correctly, reducing the risk of memory leaks and crashes.

Cons(Disadvantages)

  1. Data Loss: When converting from a larger data type to a smaller one, such as from double to int, there is a risk of losing information.
  2. Precision Loss: Converting between floating-point types of different precision (e.g., double to float) can result in a loss of precision.
  3. Performance Overhead: Frequent or unnecessary type conversions can introduce performance overhead, especially in performance-critical code.
  4. Risk of Overflow and Underflow: Overflow occurs when the target data type cannot represent a value because it is too large, resulting in a wrapped or truncated value.
  5. Underflow occurs when the target data type cannot represent a value because it is too small, resulting in a wrapped or truncated value.

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