C# study notes–conversion of variable types

C# study notes–Conversion of variable types

Conversion of variable type:

Conversion principle: Large ones of the same type can be installed into small ones, and forced conversion is required to install large ones into small types.

Implicit conversion:

Conversion of the same type:

 //Signed long——>int——>short——>sbyte
 long l = 1;
 int i = 1;
 short s = 1;
 sbyte sb = 1;
 //Implicit conversion int is implicitly converted to long
 //You can use a large range to install a small range of types (implicit conversion)
 l = i;
 //You cannot use a small range type to fit a large range type
 //i = l;
 l = i;
 l = s;
 l = sb;
 i = s;
 s = sb;

 ulongul = 1;
 uint ui = 1;
 ushort us = 1;
 byte b = 1;

 ul = ui;
 ul = us;
 ul = b;
 ui = us;
 ui = b;
 us = b;

 //Floating point number decimal double——>float
 decimal = 1.1m;
 double d = 1.1;
 float f = 1.1f;
 //There is no way to store double and float in the form of implicit conversion for the decimal type.
 //de = d;
 //de = f;
 //float can be implicitly converted to double
 d = f;

 //Special type bool char string
 // There is no implicit conversion between them
 bool bo = true;
 char c = 'A';
 string str = "123123";
 //Special type bool char string
 // There is no implicit conversion between them
 

Different types of conversions:

The char type can be implicitly converted to a numeric type and converted according to the corresponding ASCII code.

Unsigned cannot implicitly store signed, while signed can store unsigned.

Show Transformation

1. Forced bracket conversion (pay attention to accuracy issues and range issues)

   //Signed type
    int i=1;
    short s=(short)i;
    //unsigned type
    byte b=1;
    uint ui=(uint)b;
    //Floating point number
    float f=1.5f;
    double d=1.5;
    f=(float)d;
    //Unsigned and signed
    //Make sure to be positive and pay attention to the range
    int ui2=1;
    int i2=1;
    ui2=(uint)i2;
    //floating point and integer
    i2=(int)1.25f;
    //char and numerical types
    i2='A';
    char c=(char)i2;
    

2. Parse method

   //Parse conversion
    int i4=int.Parse("123");
    float f4=float.Parse("12.3");
    //Pay attention to type and scope!
    

3. Convert method

   int a=Convert.ToInt32("12");
    a=Convert.ToInt32("1.35f");//will be rounded
    a=Convert.ToInt32(true);//convert to 1 false to 0
    

   Note: In the Convert conversion, the variable is int, for example, INT16 is int, ToSingle is float

   ToDouble is double, ToBoolean is bool;

4. Convert other types to string (call ToString method)

   string str=true.ToString();

   string str2=1.5f.ToString();