Java class format digital serial 80, a random number, BigDecimal

A digital class

1. About digitally formatted: java.text.DecimalFormat;

2. The number format elements:

# Any number 

, thousandth 

decimal point

 0      is not padded with zeros

Package com.bjpowernode.java_learning; 


Import the java.text.DecimalFormat; 


public  class D80_1_ { 

  public  static  void main (String [] args) { 

    // 1. Create a digital format objects 

    @ Demand: Add thousandth 

    DecimalFormat df = new new DecimalFormat ( "####, ###" ); 

    // start formatting 

    // Number The -> String 

    System.out.println (df.format ( 1234567 )); 

   

    // demand: Add thousandths , two decimal places 

    DecimalFormat DF1 = new new DecimalFormat ( "###, ### ##." );

    System.out.println (df1.format ( 1234567.123 )); 

   

    // demand: Add thousandth, a 4 decimal places, and not enough to make up zero 

    DecimalFormat DF2 = new new DecimalFormat ( "###, ### 00." ) ; 

    System.out.println (df2.format ( 1234567.123 )); 

   

   

  } 
}

二、java.math.BigDecimal

1. This type of data extremely high accuracy, suitable for financial software.

2. Financial Software type double precision is too low

Package com.bjpowernode.java_learning; 


Import java.math.BigDecimal; 


public  class D80_2_BigDecimal { 

  public  static  void main (String [] args) { 

    // create a large data 

    the BigDecimal V1 = new new the BigDecimal (10 ); 

    the BigDecimal V2 = new new the BigDecimal (10 ); 

    // do the adder 

    @ V1 + V2; // error: two reference type can not be adding 

    // must call the method of performing an addition operation 

    the BigDecimal V3 = v1.add (V2); 

    System.out.println (V3); 

   

  } 

}

Third, generates a random number

Package com.bjpowernode.java_learning; 

Import java.util.Random; 

public  class D80_3_Random { 

  public  static  void main (String [] args) { 

    // create a new random number generator 

    the Random R & lt = new new the Random (); 

    // generated int type of random number 

    // int r.nextInt = I (101); // [random number between 0-100] 

    // System.out.println (I); 

    // loop generates five random numbers 

    for ( int I = 0; I <. 5; I ++ ) { 

      System.out.println (r.nextInt ( 101 )); 

    } 

   

  } 

}

Fourth, the source code:

D80_1_DecimalFormat.java

D80_2_BigDecimal.java

D80_3_Random.java

https://github.com/ruigege66/Java/blob/master/D80_1_DecimalFormat.java

https://github.com/ruigege66/Java/blob/master/D80_2_BigDecimal.java

https://github.com/ruigege66/Java/blob/master/D80_3_Random.java

2.CSDN：https://blog.csdn.net/weixin_44630050

3. Park blog: https: //www.cnblogs.com/ruigege0000/

4. Welcomes the focus on micro-channel public number: Fourier transform public personal number, only for learning exchanges, backstage reply "gifts" to get big data learning materials

Java class format digital serial 80, a random number, BigDecimal

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