javascript - 如果在 javascript 数组中找不到输入的值，如何获取警报消息

Question

我有一个对象数组，我可以使用 for 循环遍历该数组，如果找到该值，我可以毫无问题地将其打印到页面，但我正在尝试获取一条警报消息如果未找到该值，则显示并继续询问下一个值，直到用户键入 quit。我的代码的问题是，如果找不到值，则警报消息会一直出现，直到循环结束。这是我的代码:

var message = '';
var student;
var search;

function print(message) {
  var outputDiv = document.getElementById('output');
  outputDiv.innerHTML = message;
}

function getStudentReport( student ) {
  var report = '<h2>Student: ' + student.name + '</h2>';
  report += '<p>Track: ' + student.track + '</p>';
  report += '<p>Points: ' + student.points + '</p>';
  report += '<p>Achievements: ' + student.achievements + '</p>';
  return report;
}

function findStudent( look ){

    for (var i = 0; i < students.length; i += 1) {
        student = students[i];
        if (look === student.name) {
          message += getStudentReport( student );
          print(message);
        } else{
            alert(look + ' was not found');
        }

    }
    print(message);
}


while (true){
  search = prompt('Search student records: type a name [Jody] (or type "quit" to end)');
    if (search === null || search === 'quit'){
        break;
    }
  findStudent(search); 

}

感谢任何帮助。谢谢。

Answer 1

我认为这对您有帮助https://codepen.io/kalaiselvan/pen/YQGbar

    var message = '';
    var student;
    var search;
    function print(message) {
      var outputDiv = document.getElementById('output');
      outputDiv.innerHTML = message;
    }

    function getStudentReport( student ) {
      var report = '<h2>Student: ' + student.name + '</h2>';
      report += '<p>Track: ' + student.track + '</p>';
      report += '<p>Points: ' + student.points + '</p>';
      report += '<p>Achievements: ' + student.achievements + '</p>';
      return report;
    }

    function findStudent( look ){
    var flag=0;
        for (var i = 0; i < students.length; i += 1) {
            student = students[i];      
            if (look === student.name) {
              message += getStudentReport( student );        
              print(message);  
              flag=0;
              break;
            } else{          
              flag=1;
            }
        }
      if(flag==1){
        alert(look + ' was not found');
        showprompt();
      }   
    }

    function showprompt(){
      search = prompt('Search student records: type a name [Jody] (or type "quit" to end)');
      if (search != null && search !== "quit"){    
          findStudent(search); 
      }
    }
    showprompt();