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以数组的形式打印数组

打印方法：Arrays.toString(数组名)

public class Test {public static void main(String[] args) {int[] array={1,2,3,4,5};String ret = Arrays.toString(array);//或者这种System.out.println(Arrays.toString(array));System.out.println(ret);}
}

数组排序大小

排序方法是 Arrays.sort(数组名)

public class Test {public static void main(String[] args) {int[] array={7,18,5,27,100};System.out.println(Arrays.toString(array));Arrays.sort(array);//排序方法System.out.println(Arrays.toString(array));}
}

创建一个自己的打印数组的方法

用循环打印[ ]、数字还有标点符号

要记得打印数组的方法是：Arrays.toString(数组名)

public class Test {public static void main(String[] args) {int[] array = {7, 18, 5, 27, 100};System.out.println(myToString(array));Arrays.sort(array);//排序方法System.out.println(myToString(array));int[] array1 = null;//当数组为空时，打印nullSystem.out.println(myToString(array1));int[] array2={ };//当数组为0时，打印[]System.out.println(myToString(array2));}public static String myToString(int[] array){if(array==null){return null;}if(array.length==0 ){return "[]";}String ret ="[";for (int i = 0; i <array.length ; i++) {ret += array[i]+" ";if(i != array.length-1){ret += ",";}}ret += "]";return ret;}
}

自己创建一个冒泡排序

两数之间交换方法

    //冒泡排序
public class Test {public static void main(String[] args) {int[] array={2,1,8,16,22,7};Bubblesort(array);Arrays.sort(array);//给数组排序大小System.out.println(Arrays.toString(array));}public static void Bubblesort(int [] array){if(array==null){return ;}for (int i = 0; i < array.length; i++) {boolean flg =false;//优化代码时间复杂度for (int j = 0; j <array.length-1-i ; j++) {int tmp = 0;if(j>j+1){tmp =array[j] ;array[j] = array[j+1];array[j+1] =tmp;flg =true;}}if(!flg){return ;}}}
}

逆置数组打印

核心思路还是 i 和 j 交换

public class Test {public static void main(String[] args) {int[] array={2,3,4,5};reverse(array);System.out.println(Arrays.toString(array));}public static void reverse(int[] array){if(array==null){return ;}int i=0;int j=array.length-1;//当i>=j时说明已经交换完//要有条件让交换停下来while(i<j){int tmp= array[i];array[i] = array[j];array[j] = tmp;i++;j--;}}
}

总结

今天的复习收获蛮多，学到了数组的打印方法和排序方法，也学到了逆置打印数组和如何用数组创建一个冒泡排序