英文:
Print only once in for loop if cannot find an ID
问题
我能够打印出一条消息，如果学生ID可用，但如果未找到ID，我只想要打印一次 println。
以下是我删除学生的代码：
public void removeStudent(int studentId) {
for (int i = 0; i < students.size(); i++) {
if (students.get(i).getId() != studentId) {
continue;
}
System.out.println("已删除包含ID#: " + studentId + " 信息的档案。");
this.students.remove(i);
students = new ArrayList<>();
return;
}
}
英文:
I was able to print a message if a student ID is available, but I want to only print a println once if the ID was not found.
below is my code for removing a student
public void removeStudent(int studentId) {
for (int i = 0; i < students.size(); i++) {
if (students.get(i).getId() != studentId) {
continue;
}
System.out.println("Deleted a profile containing information for ID#: " + studentId + ".");
this.students.remove(i);
students = new ArrayList<>();
return;
}
}
答案1
得分: 1
为什么你不在java.util.List中使用任何方法呢？
我的意思是，如果我必须编写一个删除一个（或重复的）id并且打印一些内容的方法，我会写出类似这样的代码：
public void removeStudent(int studentId) {
if (students.contains(studentId)) {
students.removeIf(id -> id == studentId);
System.out.println("已删除包含ID＃的信息档案：" + studentId + "。");
}
else
System.out.println("无内容可删除。");
}
但是，如果你不想改变你的代码太多，你可以做类似这样的修改：
public void removeStudent(int studentId) {
for (int i = 0; i < students.size(); i++) {
if (students.get(i).getId() != studentId) {
continue;
}
System.out.println("已删除包含ID＃的信息档案：" + studentId + "。");
this.students.remove(i);
students = new ArrayList<>();
return;
}
System.out.println("未找到ID。");
}
我相当确定使用流（stream）可以使这个任务比这两段代码更顺畅。
祝好，
英文:
why do you not use any method in java.util.List ?
I mean, if I have to write a method who delete one (or duplicate) id and print something I would write something like this
public void removeStudent(int studentId) {
if( students.contains(studentId)) {
students.removeIf(id -> id==studentId);
System.out.println("Deleted a profile containing information for ID#: " + studentId + ".");
}
else
System.out.println("nothing to delete");
}
But if you don't want to change your code to much you can just do something like this
public void removeStudent(int studentId) {
for (int i = 0; i < students.size(); i++) {
if (students.get(i).getId() != studentId) {
continue;
}
System.out.println("Deleted a profile containing information for ID#: " + studentId + ".");
this.students.remove(i);
students = new ArrayList<>();
return;
}
System.out.println(" Id not found ");
}
And I'm pretty sure stream can make this job smoother than those 2 snippet
BR
答案2
得分: 0
基于 Tim 的回答，我建议移除 break 语句以删除所有具有相同 id 的学生，但仅打印一次：
public boolean removeStudent(int studentId) {
boolean removed = false;
for (int i=0; i < students.size(); i++) {
if (students.get(i).getId() == studentId) {
System.out.println("已删除包含 ID# " + studentId + " 信息的档案。");
this.students.remove(i);
removed = true;
}
}
return removed;
}
英文:
Based on answer of Tim, I'd recommend remove the break to delete all students with the same id, but print only once:
public boolean removeStudent(int studentId) {
boolean removed = false;
for (int i=0; i < students.size(); i++) {
if (students.get(i).getId() == studentId) {
System.out.println("Deleted a profile containing information for ID#: " + studentId + ".");
this.students.remove(i);
removed = true;
}
}
return removed;
}
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