C - Data Types

  1. Tác giả: LTTK CTV
    Đánh giá: ✪ ✪ ✪ ✪ ✪

    Data types in c refer to an extensive system used for declaring variables or functions of different types. The type of a variable determines how much space it occupies in storage and how the bit pattern stored is interpreted.

    The types in C can be classified as follows:


    [​IMG]

    The array types and structure types are referred collectively as the aggregate types. The type of a function specifies the type of the function's return value. We will see the basic types in the following section, where as other types will be covered in the upcoming chapters.

    Integer Types
    The following table provides the details of standard integer types with their storage sizes and value ranges:

    Type Storage size Value range


    [​IMG]

    To get the exact size of a type or a variable on a particular platform, you can use the sizeof operator. The expressions sizeof(type) yields the storage size of the object or type in bytes. Given below is an example to get the size of int type on any machine −

    Mã (Javascript):
    1. #include <stdio.h>
    2. #include <limits.h>
    3.  
    4. int main() {
    5.  
    6. printf("Storage size for int : %d \n", sizeof(int));
    7.  
    8. return 0;
    9. }
    When you compile and execute the above program, it produces the following result on Linux:

    Mã (Text):
    1. Storage size for int : 4
    Floating-Point Types
    The following table provide the details of standard floating-point types with storage sizes and value ranges and their precision −

    Type Storage size Value range Precision


    [​IMG]

    The header file float.h defines macros that allow you to use these values and other details about the binary representation of real numbers in your programs. The following example prints the storage space taken by a float type and its range values −

    Mã (Javascript):
    1. #include <stdio.h>
    2. #include <float.h>
    3.  
    4. int main() {
    5.  
    6. printf("Storage size for float : %d \n", sizeof(float));
    7. printf("Minimum float positive value: %E\n", FLT_MIN );
    8. printf("Maximum float positive value: %E\n", FLT_MAX );
    9. printf("Precision value: %d\n", FLT_DIG );
    10.  
    11. return 0;
    12. }
    When you compile and execute the above program, it produces the following result on Linux −

    Mã (Text):
    1. Storage size for float : 4
    2. Minimum float positive value: 1.175494E-38
    3. Maximum float positive value: 3.402823E+38
    4. Precision value: 6
    The void Type
    The void type specifies that no value is available. It is used in three kinds of situations −


    [​IMG]