Tenth week (11.18-11.24)----Personal project----Learning Java Summary 2

First, get the random number

Method 1 (data type) (minimum value +math.random () * (max-min. +1)), note that each parenthesis here is best not omitted.

Cases:

1      Public Static voidMain (string[] args) {2         //TODO auto-generated Method Stub3          for(inti = 0;i<30;i++){4             intSuijishu = (int) (1+math.random () * (10-1+1));//gets the random number from 1 to 10 and converts it to an integer type5System.out.print (suijishu+ ";"));6         }7}

Operation Result:

Method 2 obtains the random number by java.util the Nextxxx () method of the random class in the package. The Nextint (k) method can return the random integer number of the 0-k , and the results are as follows.

Cases:

1      Public Static voidMain (string[] args) {2         //TODO auto-generated Method Stub3Random r =NewRandom ();4          for(inti = 0;i<30;i++)5         {6System.out.print (R.nextint (4) + ";");7         }8}

Results:

Nextdouble () gets a random double number, which is obtained by nextdouble () * (b-a) +a to get the double random number of the interval in [A, b] .

Cases:

1      Public Static voidMain (string[] args) {2         //TODO auto-generated Method Stub3Random r =NewRandom ();4         DoubleA = 0.0,b = 0.2;//interval in [0.0,0.2]5         6          for(inti = 0;i<30;i++)7         {8System.out.println (R.nextdouble () * (b-a) +a+ ";);9         }Ten}

Results:

Second, integer conversion to String type

Method 1 valueof method for string

Cases:

1  Public Static void Main (string[] args) {2         // TODO auto-generated Method Stub 3         int i=5; 4         String s=string.valueof (i); 5         System.out.println (s); 6 7     }

Results:

Method two adds an empty string directly after the int

Cases:

1  Public classSuijishu {2 3      Public Static voidMain (string[] args) {4         //TODO auto-generated Method Stub5         intI=5;6String s = i+ "";7 System.out.println (s);8 9     }Ten  One}

Results:

　

Method Three: Use int's wrapper class integer, and use his tostring method in the integer.

Cases:

1      Public Static void Main (string[] args) {2         // TODO auto-generated Method Stub 3         int i=5; 4         String s = integer.tostring (i);; 5         System.out.println (s); 6 7     }

Results:

Tenth week (11.18-11.24)----Personal project----Learning Java Summary 2