排序--[冒泡，Arrays.sort]

冒泡：

public class Test01 {

public static void main(String[] args){

int [] a={12,25,3,54,24,69};

for (int i = 1; i < a.length; i++) { //若i从0开始，则i<a.length-1；i从1开始，则i<a.length

for (int j = 0; j < a.length-1; j++) { //j要比数组的长度少一且必须从0开始，否则当j=a.length-1,

if (a[j]>a[j+1]) { //就会有j+1=a.length

int temp = a[j]; //导致最后一个a[j+1]会溢出数组，造成数组溢出异常

a[j] = a[j+1];

a[j+1] = temp;

}

}

}

for (int i = 0; i < a.length; i++) {

System.out.print(a[i]+"\t");

}

}

}

------------------------------------------------------------------------

Arrays.sort：

import java.util.Arrays;

public class Test03 {

public static void main(String[] args){

int [] a={12,25,3,54,24,69};

Arrays.sort(a);

System.out.print(Arrays.toString(a));

}

}