javascript - 更新后的变量未在函数外读取

Question

我有一个 ajax 调用，成功后，我将 received 的值增加 1。getMessage() 应该只在 received < 10 为真时输入。但是函数外received的返回值始终为0，导致while无限循环。

有人有任何建议可以在函数外部看到更新后的接收值吗？

var received = 0;

while (received < 10) {
    getMessage();
}

function getMessage() {
    $.ajax({
        url: '/Home/getData/',
        type: "GET",
        success: function(result) {
            received += 1;
        }
    });
    console.log(received);
}
}
});
}

Answer 1

我强烈建议您阅读重复的帖子。但是，这是解决您尝试使用异步方法的问题的一种可能解决方案。

var received = 0;

//received is < 10, start loop
getMessage();

function getMessage() {
  $.ajax({
    url: '/Home/getData/',
    type: "GET",
    success: function(result) {
      received++; //increment
      
      if (received < 10) {
        console.log(received);
        getMessage();
      }
    }
  });
}