java简单实现数组的增删改查方法

public static void main(String[] args){
		//静态初始化1
		//String[] names = new String[]{"小明","小红","铁蛋","二狗","大傻子"};
		//静态初始化2
		//String[] names;
		//names = new String[]{"小明","小红","铁蛋","二狗","大傻子"};
		//静态初始化3
		String[] names = {"小明","小红","铁蛋","二狗","大傻子"};
		//设置指定下标上的元素
		names[3] = "大狗";
		//获取指定下标上的元素
		String n = names[3];
		System.out.println("获取指定下标上的元素：" + n);//林成
		//ArrayIndexOutOfBoundsException - 数组下标越界异常
		//System.out.println(names[100]);
		//获取元素个数
		int len = names.length;
		System.out.println("获取元素个数：" + len);//5
		System.out.println("-----------");
		//遍历 - for循环
		for(int i = 0;i<names.length;i++){
			System.out.println(names[i]);
		}
		System.out.println("-----------");
		//遍历 - foreach(增强for循环)
		for(String str:names){//遍历数组，依次把元素赋值给str
			System.out.println(str);
		}
		/**
			遍历时要使用到下标，就用for循环遍历
			遍历时要不使用到下标，就用foreach遍历	
		*/
	}

public static void main(String[] args){
		//动态初始化1
		String[] names = new String[5];//5->5个长度
		//设置指定下标上的元素
		names[0] = "小明";
		names[1] = "铁蛋";
		names[2] = "二狗";
		//获取指定下标上的元素
		String n = names[2];
		System.out.println("获取指定下标上的元素：" + n);//二狗
		//ArrayIndexOutOfBoundsException - 数组下标越界异常
		//System.out.println(names[100]);
		//获取元素个数
		int len = names.length;
		System.out.println("获取元素个数：" + len);//5
		System.out.println("-----------");
		//遍历 - for循环
		for(int i = 0;i<names.length;i++){
			System.out.println(names[i]);
		}
		System.out.println("-----------");
		//遍历 - foreach(增强for循环)
		for(String str:names){//遍历数组，依次把元素赋值给str
			System.out.println(str);
		}
		/**
			遍历时要使用到下标，就用for循环遍历
			遍历时要不使用到下标，就用foreach遍历	
		*/

public static void main(String[] args){
		//源数组
		String[] names = {"小明","小红","铁蛋","二狗"};
		//新数组
		//(names.length>>1在此次可以理解为(names.length/2)
		int capacity = names.length + (names.length>>1);//新容量：是源数组长度的1.5倍
		String[] newNames = new String[capacity];
		//把源数组所有的数据迁移到新数组中
		for(int i = 0;i<names.length;i++){
			newNames[i] = names[i];
		}
		//将新数组的地址赋值给源数组
		names = newNames;
		//遍历源数组
		for(String name:names){
			System.out.println(name);
		}
	}

public class Test111 {
	public static void main(String[] args){
	    //源数组
	    String[] names = {"小明","小红","铁蛋","二狗"};
	    //新数组
	    String[] newNames = names;
	    //遍历新数组
	    System.out.print("修改原数据前：");
	    for(String name : newNames){
	        System.out.print(name+"\t");
	    }
	    System.out.println();
	    //修改源数组
	    names[0] = "大傻子";
	    //遍历新数组
	    System.out.print("修改原数据后：");
	    for(String name : newNames){
	        System.out.print(name+"\t");
	    }
	    System.out.println();
	}
}

public static void main(String[] args){
		//源数组
		String[] names = {"小明","小红","铁蛋","二狗"};
		//新数组
		String[] newNames = new String[names.length];
		//将源数组中数据依次赋值给新数组
		for(int i = 0;i<names.length;i++){
			newNames[i] = names[i];
		}
		//修改源数组
		names[0] = "大聪明";
		//遍历新数组
		for(String name : newNames){
			System.out.println(name);
		}
	}

public static void main(String[] args){
		//源数组
		String[] names = {"小明","小红","铁蛋","二狗"};
		//新数组
		String[] newNames = new String[names.length-1];
		//将源数组的数据迁移到新数组中，要删除的元素(深田咏美)除外
		int index = 0;//新数组的下标
		for(String name:names){
			if(!name.equals("小红")){
				newNames[index] = name;
				index++;
			}
		}
		//将新数组的地址赋值给源数组
		names = newNames;
		//遍历源数组
		for(String name:names){
			System.out.println(name);
		}
	}

public static void main(String[] args){
		//源数组
		String[] names = {"小明","小红","铁蛋","二狗"};
		//数据的迁移
		for(int i = 1;i<names.length-1;i++){
			names[i] = names[i+1];
		}
		names[names.length-1] = null;
		//遍历源数组
		for(String name:names){
			System.out.println(name);
		}
	}

public static void main(String[] args){
		int[] is = {39,77,27,20,45,62};
		for(int i = 0;i<is.length-1;i++){
			for(int j = 0;j<is.length-1-i;j++){
				if(is[j] > is[j+1]){
					int temp = is[j];
					is[j] = is[j+1];
					is[j+1] = temp;
				}
			}
		}
		for(int num : is){
			System.out.println(num);
		}
	}

public static void main(String[] args){
	import java.util.Arrays;
    int[] a={1,5,8,6};
    for(int num : a){
		System.out.println(num);
	}
}

for(int i = 0;i<is.length;i++){
			if(is[i] == num){
				System.out.println("查找到了");
			}
		}

public static void main(String[] args){
		int[] is = {39,77,27,20,45,62};
		int num = 77;
		//排序
		Arrays.sort(is);
		int start = 0;
		int end = is.length-1;
		while(start <= end){
			int mid = (start+end)/2;
			if(num >is[mid]){
				start = mid+1;
			}else if(num < is[mid]){
				end = mid-1;
			}else{
				System.out.println("查找到了");
				break;
			}
		}
	}