如果第一个输入是“ Dog”,第二个输入是“ Wolf”,第三个输入是“ Cat”。结果将如下所示:
Dog | Wolf | Wolf | Cat | Cat | Cat |
是我的forloop导致此迭代过于频繁吗?
public class LabTextManipulation {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
ArrayList<String> parks = new ArrayList<String>();
String enteredPark;
StringBuilder sb = new StringBuilder();
boolean stop = true;
while (stop == true) {
System.out.println("Please enter your favorite National Park or Done to stop: ");
enteredPark = input.nextLine();
if (!"Done".equalsIgnoreCase(enteredPark)) {
parks.add(new String(enteredPark));
for (int i = 0; i < parks.size(); i++) {
sb.append(enteredPark + " | ");
}//end for
} else {
stop = false;
}
}
String nationalParks = sb.toString();
System.out.println(nationalParks);
}
}
预期:
" Dog | Wolf | Cat |"
实际:
" Dog | Wolf | Wolf | Cat | Cat | Cat |"
最佳答案
这是造成问题的原因
for(int i = 0;i < parks.size(); i++ ) {
sb.append(enteredPark + " | ");
}
每次将新字符串添加到
parks
时,都将在下一次迭代中将增加的重复值添加到sb的计数-我相信您根本不应该使用循环if(!"Done".equalsIgnoreCase(enteredPark)) {
parks.add(enteredPark); // also don't create new String here
sb.append(enteredPark + " | ");
}
关于java - StringBuilder根据索引输出?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/57778606/