Question

对于我的一个课程，我们的任务是创建一个利用用户时间的简单javascript函数。我做了一个计算器，告诉你如果你现在就去睡觉什么时候醒来，但是我遇到了输出分钟的问题。

对于分钟，如果它们小于10，我之前加0，所以它的7:05不是7：5。但是因为它将0添加到分钟变量。在我使用分钟

的剩余时间里，它一直停留在那里

因此它适用于3:08的0，然后在其余用途中保留它。

下面是我的javascript，我想我只需要缩短变量分钟，只允许保留两个字符，但我不知道该怎么做。

var time = new Date();
var hours = time.getHours();
var minutes = time.getMinutes();
var amPM = "am";

if (hours > 12) {
  hours = hours - 12;
  amPM = "pm"
}

document.getElementById("currentTime").innerHTML = hours + ':' + minutes + ' ' + amPM;


function checkTime(i) {
  if (i < 10) {
    i = "0" + i
  }; // add zero in front of numbers < 10
  return i;
}

function sleepFunction() {

  var time = new Date();
  var hours = time.getHours();
  var minutes = time.getMinutes();
  var amPM = "pm";
  var fixmin = "0";


  if (hours >= 12) {
    hours = hours - 12;
    amPM = "pm"
  }
  if (minutes < 10) {
    minutes = fixmin + minutes;
  }

  var hours = hours + 1;
  var minutes = minutes + 52;

  if (minutes >= 60) {
    hours = hours + 1;
    minutes = minutes - 60;
  }
  if (minutes < 10) {
    minutes = fixmin + minutes;
  }
  if (hours >= 12) {
    hours = hours - 12;
    amPM = "pm"
  }

  document.getElementById("demo").innerHTML = hours + ':' + minutes + ' ' + amPM;
  var hours = hours + 1;
  var minutes = minutes + 15;

  if (minutes >= 60) {
    hours = hours + 1;
    minutes = minutes - 60;
  }
  if (minutes < 10) {
    minutes = fixmin + minutes;
  }
  if (hours >= 12) {
    hours = hours - 12;
    amPM = "pm"
  }

  document.getElementById("demo1").innerHTML = hours + ':' + minutes + ' ' + amPM;
  var hours = hours + 1;
  var minutes = minutes + 30;

  if (minutes >= 60) {
    hours = hours + 1;
    minutes = minutes - 60;
  }
  if (minutes < 10) {
    minutes = fixmin + minutes;
  }

  if (hours > 12) {
    hours = hours - 12;
    amPM = "pm"
  }
  document.getElementById("demo2").innerHTML = hours + ':' + minutes + ' ' + amPM;
  var hours = hours + 1;
  var minutes = minutes + 30;

  if (minutes >= 60) {
    hours = hours + 1;
    minutes = minutes - 60;
  }
  if (minutes < 10) {
    minutes = fixmin + minutes;
  }

  if (hours > 12) {
    hours = hours - 12;
    amPM = "am"
  }
  document.getElementById("demo3").innerHTML = hours + ':' + minutes + ' ' + amPM;
  var hours = hours + 1;
  var minutes = minutes + 30;


  if (minutes >= 60) {
    hours = hours + 1;
    minutes = minutes - 60;
  }
  if (minutes < 10) {
    minutes = fixmin + minutes;
  }
  if (hours > 12) {
    hours = hours - 12;
    amPM = "am"
  }


  document.getElementById("demo4").innerHTML = hours + ':' + minutes + ' ' + amPM;
  var hours = hours + 1;
  var minutes = minutes + 30;

  if (minutes >= 60) {
    hours = hours + 1;
    minutes = minutes - 60;
  }
  if (minutes < 10) {
    minutes = fixmin + minutes;
  }
  if (hours > 12) {
    hours = hours - 12;
    amPM = "am"
  }

  document.getElementById("demo5").innerHTML = hours + ':' + minutes + ' ' + amPM;


  document.getElementById("averageWarning").innerHTML = "It Takes the Average Human 18 Minutes to Fall Aleep after viewing a screen";
  document.getElementById("sleepNow").innerHTML = "If you go to bed right now, you should set your alarm for one of these times";
}

Answer 1

鉴于它只是一个显示问题，您可以在任何时候想要显示分钟时使用 checkTime 功能。

例如：

document.getElementById("demo5").innerHTML = hours + ':' + checkTime(minutes) + ' ' + amPM;

小提琴示例：https://jsfiddle.net/u3weyw6s/1/

删除变量的一部分

1 个答案: