array1.java

几个简单的java学习代码

import java.util.Arrays;
import java.util.Random;

public class Array1 {
  static Random r = new Random();
  static String ssource =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
    "abcdefghijklmnopqrstuvwxyz";
  static char[] src = ssource.toCharArray();
  // Create a random String
  public static String randString(int length) {
    char[] buf = new char[length];
    int rnd;
    for(int i = 0; i < length; i++) {
      rnd = Math.abs(r.nextInt()) % src.length;
      buf[i] = src[rnd];
    }
    return new String(buf);
  }
  // Create a random array of Strings:
  public static
  String[] randStrings(int length, int size) {
    String[] s = new String[size];
    for(int i = 0; i < size; i++)
      s[i] = randString(length);
    return s;
  }
  public static void print(byte[] b) {
    for(int i = 0; i < b.length; i++)
      System.out.print(b[i] + " ");
    System.out.println();
  }
  public static void print(String[] s) {
    for(int i = 0; i < s.length; i++)
      System.out.print(s[i] + " ");
    System.out.println();
  }
  public static void main(String[] args) {
    byte[] b = new byte[15];
    r.nextBytes(b); // Fill with random bytes
    print(b);

    Arrays.sort(b);
    print(b);
    int loc = Arrays.binarySearch(b, b[10]);
    System.out.println("Location of " + b[10] +
      " = " + loc);
    // Test String sort & search:
    String[] s = randStrings(4, 10);
    print(s);
    Arrays.sort(s);
    print(s);
    loc = Arrays.binarySearch(s, s[4]);
    System.out.println("Location of " + s[4] +
      " = " + loc);
  }
}


运行结果：

3 47 -98 108 100 -50 80 122 124 5 24 -121 -97 -69 -106 
-121 -106 -98 -97 -69 -50 3 5 24 47 80 100 108 122 124 
Location of 80 = 10
VSRk kAuy hEMe jMQf MySk RTge xAIG HqjC NFKR vBhH 
HqjC MySk NFKR RTge VSRk hEMe jMQf kAuy vBhH xAIG 
Location of VSRk = 4