Java字符串笔记手札，手写笔记练练字！

老家没得空调， 久坐电脑旁迟早会热死，扭扭歪歪写了几个字，发现真的丑，字还得练练，所以试试手写笔记拍照上传博客，希望别喷我字丑，谢谢！

关于String的常用方法:

关于从控制台读取字符串/字符:

关于字符串比较:

关于字符串截取：

关于格式化输出printf():

一些代码练习:

// 姓名分割
public  void stringTest(){
 
        Scanner in = new Scanner(System.in);
        System.out.print("enter a string of you name:");
        String s = in.nextLine();
        int k = s.indexOf(' ');
        String firstName = s.substring(0, k);
        String lastName = s.substring(k+1);
        System.out.println("The firstName is "+ firstName +"\nThe lastName is " + lastName);
    }
    

// 十六进制转化十进制
public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        System.out.print("Enter a hex digit:");
        String hexDigit = in.nextLine();

        // 如果输入不是单个字符
        if (hexDigit.length() != 1){
            System.out.println("You must enter one character");
            System.exit(1);
        }
        // 数值转换
        char ch = Character.toUpperCase(hexDigit.charAt(0));
        if (ch >= 'A' && ch <= 'F'){
            int values = ch - 'A' + 10;
            System.out.println("The change values for hex digit" + ch + " is " + values);
        }
        else if(Character.isDigit(ch)){
            System.out.println("The change values for hex digit" + ch + " is " + ch);
        }else {
            System.out.println("The " + ch + "char not hex digit, is error enter!");
        }

    }

我java很捞逼，还在探索，轻点喷。