javascript - 条件语句无法正常运行

Question

取决于一天中的时间。我正在尝试使用 JavaScript ( new Date() ) 方法向用户显示上午、下午或晚上。但我收到的回应只是(其他)声明。我可以获得关于我做错了什么的建议吗？

const mainHeader = document.getElementById("header");

var greetings = () => {
    var today = new Date();
}

window.onload= (e) => {
    greetings;


    if(today >= 1 && today < 12) {
        mainHeader.innerHTML = "<h3>Good Morning! And Welcome To Guess The Number</h3>"
        console.log("Morning: between 1 and 12");
    }  else if(today >= 12 && today < 17) {
            mainHeader.innerHTML = "<h3>Good Afternoon! And Welcome To Guess The Number</h3>"
            console.log("Afternoon: between 12 and 17");
    }  else if(today >= 17 && today <= 24) {
        mainHeader.innerHTML = "<h3>Good Evening! And Welcome To Guess The Number</h3>"
        console.log("Evening: between 17 and 24");
    }  else {
            mainHeader.innerHTML = "<h3>Welcome to Guess The Number</h3>"
            console.log("No time zone");
    }
}

Answer 1

您需要从 greetings() 返回小时，然后将其分配给 window.onload 函数中的变量。

const mainHeader = document.getElementById("header");

var greetings = () => {
  var today = new Date();
  return today.getHours();
}

window.onload = (e) => {
  var today = greetings()
  if (today >= 1 && today < 12) {
    mainHeader.innerHTML = "<h3>Good Morning! And Welcome To Guess The Number</h3>"
    console.log("Morning: between 1 and 12");
  } else if (today >= 12 && today < 17) {
    mainHeader.innerHTML = "<h3>Good Afternoon! And Welcome To Guess The Number</h3>"
    console.log("Afternoon: between 12 and 17");
  } else if (today >= 17 && today <= 24) {
    mainHeader.innerHTML = "<h3>Good Evening! And Welcome To Guess The Number</h3>"
    console.log("Evening: between 17 and 24");
  } else {
    mainHeader.innerHTML = "<h3>Welcome to Guess The Number</h3>"
    console.log("No time zone");
  }
}

<div id="header">
</div>