java - 验证搜索 arrayList

Question

嗨，我已经创建了搜索数组列表的代码，如果这里找不到任何内容，我需要能够打印一行，这就是我所拥有的。

            for (int i = 0; i < trackNum.size(); i++) { //looping arrayList trackNum
            if(trackNum.get(i).equals(trackNumber)){ //searching for matches to trackNumber
                System.out.println(trackNum.get(i) + ": " + name.get(i) + " " + duration.get(i)); //printing out the matches            
            } else{
                System.out.println("Not Tracks Found for " + trackNumber);
            }
        }

目前它不会打印出 else 行，它只是保持空白。

Answer 1

您应该只在迭代整个列表后打印“未找到”消息:

        boolean found = false;
        for (int i = 0; i < trackNum.size(); i++) { //looping arrayList trackNum
            if(trackNum.get(i).equals(trackNumber)){ //searching for matches to trackNumber
                System.out.println(trackNum.get(i) + ": " + name.get(i) + " " + duration.get(i)); //printing out the matches            
                found = true;
                break;
            }
        }   
        if (!found) {
            System.out.println("Not Tracks Found for " + trackNumber);
        }