Java字符串练习

        StringAPI Exercise

package JavaExercise120240827;public class JavaExercise1 {public static void main(String[] args) {// String API ExerciseString str = "hello world";// 返回字符串长度（包括空白字符）int length = str.length();System.out.println(length);// 将字符串的每一个元素取出，构建一个byte数组（值就是ASCII码）byte[] bytes = str.getBytes();for (byte b : bytes) {System.out.print((char)b);}System.out.println();// 将字符串转换为大写（小写）str = str.toUpperCase();System.out.println(str);str = str.toLowerCase();System.out.println(str);// 切割子串，包头不包尾str = str.substring(0, 5);}
}