从Java字符串中提取值

String str = "Hello World";
String extractedValue = str.substring(0, 5);
System.out.println(extractedValue); // Output: Hello

String str = "apple,banana,orange";
String[] values = str.split(",");
System.out.println(values[0]); // Output: apple
System.out.println(values[1]); // Output: banana
System.out.println(values[2]); // Output: orange

import java.util.regex.Matcher;
import java.util.regex.Pattern;

String str = "abc123def456";
Pattern pattern = Pattern.compile("\\d+"); // 匹配一个或多个数字
Matcher matcher = pattern.matcher(str);

while (matcher.find()) {
    String extractedValue = matcher.group();
    System.out.println(extractedValue);
}
// Output: 123
// Output: 456