C # console formatting output summary

Format a number

Description of format characters and associated attributes

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C and C currency formats.

In decimal format.

E, E scientific count (INDEX) format.

F and F are fixed points.

G.

N, N numeric format.

The r and R round-trip formats Ensure that the number converted to a string has the same value as the original number when being converted back to a number.

X and X hexadecimal formats.

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Example:

 Double val = Math. PI; Console. WriteLine (val. ToString (); // displays 3.14159265358979
Console. WriteLine (val. ToString ("E"); // displays 3.141593E + 000
Console. WriteLine (val. ToString ("F3"); // displays 3.142
Single val2 = 0.123F; Console. WriteLine (val2.ToString ("p"); // displays 12.30%
Console. WriteLine (val2.ToString ("p1"); // displays 12.3%
Int val3 = 65535;
Console. WriteLine (val3.ToString ("x"); // displays ffff
Console. WriteLine (val3.ToString ("X"); // displays FFFF
Decimal val4 = 323.42313 m;
Console. WriteLine ("{0, 9: f2}", val4); // displays 323.42
// {0th: f2} indicates the first parameter, which occupies the right alignment of 9 digits and has two accurate decimal places.
Console. WriteLine ("{0,-9: f2}", val4); //-9 indicates 9 digits, left aligned

By default, a space is placed between the digit and the percent sign. The customization method is as follows:

The NumberFormatInfo class is a member of the System. Globalization namespace. Therefore, the namespace must be imported to the program.

 Single val=0.123F;

object myobj=NumberFormatInfo.CurrentInfo.Clone( ) as NumberFormatInfo;

NumberFormatInfo myformat=myobj as NumberFormatInfo;

myformat.PercentPositivePattern=1;

Console.WriteLine(val.ToString("p",myformat)); //displays 12.30%;

Console.WriteLine(val.ToString("p1",myformat)); //displays 12.3%;

 

Formatting is flexible. The following example demonstrates a meaningless currency structure:

 Double val = 1234567.89;

Int [] groupsize = {2, 1, 3 };

Object myobj = NumberFormatInfo. CurrentInfo. Clone ();

NumberFormatInfo mycurrency = myobj as NumberFormatInfo;

Mycurrency. CurrencySymbol = "#"; // symbol

Mycurrency. CurrencyDecimalSeparator = ":"; // decimal point

Mycurrency. CurrencyGroupSeparator = "_"; // delimiter

Mycurrency. CurrencyGroupSizes = groupsize;

Console. WriteLine (val. ToString ("C", mycurrency ));

 

// Output #1_234_5_67: 89

Format date

The output format depends on the cultural settings of the user's computer.

 using System;

using System.Globalization;

public class MainClass

{

　　public static void Main(string[] args)

　　{

        DateTime dt = DateTime.Now;

        String[] format = {"d","D","f","F","g","G","m","r","s","t",                           "T","u", "U","y","dddd, MMMM dd yyyy",                          "ddd, MMM d \"'\"yy","dddd, MMMM dd","M/yy","dd-MM-yy",};

        String date;

for (int i = 0; i < format.Length; i++)

      {

         date = dt.ToString(format, DateTimeFormatInfo.InvariantInfo);

         Console.WriteLine(String.Concat(format, " :" , date));

      }

     }

}

D: 07/11/2004 <===== output

D: Sunday, 11 July 2004

F: Sunday, 11 July 2004

F: Sunday, 11 July 2004 10:52:36

G: 07/11/2004

G: 07/11/2004 10:52:36

M: July 11

R: Sun, 11 Jul 2004 10:52:36 GMT

S: 2004-07-11T10: 52: 36

T: 10: 52

T: 10: 52: 36

U: 2004-07-11 10: 52: 36Z

U: Sunday, 11 July 2004 02:52:36

Y: 2004 July

Dddd, MMMM dd yyyy: Sunday, July 11 2004

Ddd, MMM d "'" yy: Sun, Jul 11' 04

Dddd, MMMM dd: Sunday, July 11

M/yy: 7/04

Dd-MM-yy: 11-07-04

 

Format Enumeration

 enum classmen

{
    ynn=1,

    yly=2,

    css=3,

    C++=4
}

 

Obtain the enumerated string information as follows:

 classmen myclassmen=classmen.yly;

Console.WriteLine(myclassmen.ToString( ));   //displays yly

Console.WriteLine(myclassmen.ToString("d")); //displays 2

The following information is obtained from the system enumeration:

 DayOfWeek day=DayOfWeek.Friday;

//displays "Day is Friday"

Console.WriteLine(String.Format("Day is {0:G}",day));

Format the string "G" to display the enumeration as a string.