我需要在JavaScript开关语句的多个情况下,类似于:
switch (varName)
{
case "afshin", "saeed", "larry":
alert('Hey');
break;
default:
alert('Default case');
break;
}
我该怎么做呢?如果在JavaScript中没有办法做这样的事情,我想知道一个也遵循DRY概念的替代解决方案。
我需要在JavaScript开关语句的多个情况下,类似于:
switch (varName)
{
case "afshin", "saeed", "larry":
alert('Hey');
break;
default:
alert('Default case');
break;
}
我该怎么做呢?如果在JavaScript中没有办法做这样的事情,我想知道一个也遵循DRY概念的替代解决方案。
当前回答
其中一个可能的解决方案是:
const names = {
afshin: 'afshin',
saeed: 'saeed',
larry: 'larry'
};
switch (varName) {
case names[varName]: {
alert('Hey');
break;
}
default: {
alert('Default case');
break;
}
}
其他回答
更干净的处理方法
if (["triangle", "circle", "rectangle"].indexOf(base.type) > -1)
{
//Do something
}else if (["areaMap", "irregular", "oval"].indexOf(base.type) > -1)
{
//Do another thing
}
您可以为具有相同结果的多个值执行此操作
我喜欢它的清晰度和DRY语法。
varName = "larry";
switch (true)
{
case ["afshin", "saeed", "larry"].includes(varName) :
alert('Hey');
break;
default:
alert('Default case');
}
我可以看到这里有很多很好的答案,但如果我们需要检查10个以上的情况怎么办?以下是我自己的方法:
function isAccessible(varName){
let accessDenied = ['Liam', 'Noah', 'William', 'James', 'Logan', 'Benjamin',
'Mason', 'Elijah', 'Oliver', 'Jacob', 'Daniel', 'Lucas'];
switch (varName) {
case (accessDenied.includes(varName) ? varName : null):
return 'Access Denied!';
default:
return 'Access Allowed.';
}
}
console.log(isAccessible('Liam'));
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Example1</title>
<link rel="stylesheet" href="css/style.css" >
<script src="js/jquery-1.11.3.min.js" type="text/javascript"></script>
<script>
function display_case(){
var num = document.getElementById('number').value;
switch(num){
case (num = "1"):
document.getElementById("result").innerHTML = "You select day Sunday";
break;
case (num = "2"):
document.getElementById("result").innerHTML = "You select day Monday";
break;
case (num = "3"):
document.getElementById("result").innerHTML = "You select day Tuesday";
break;
case (num = "4"):
document.getElementById("result").innerHTML = "You select day Wednesday";
break;
case (num = "5"):
document.getElementById("result").innerHTML = "You select day Thusday";
break;
case (num = "6"):
document.getElementById("result").innerHTML = "You select day Friday";
break;
case (num = "7"):
document.getElementById("result").innerHTML = "You select day Saturday";
break;
default:
document.getElementById("result").innerHTML = "You select day Invalid Weekday";
break
}
}
</script>
</head>
<body>
<center>
<div id="error"></div>
<center>
<h2> Switch Case Example </h2>
<p>Enter a Number Between 1 to 7</p>
<input type="text" id="number" />
<button onclick="display_case();">Check</button><br />
<div id="result"><b></b></div>
</center>
</center>
</body>
下面是另一个易于使用的开关case语句。可以满足您的要求。我们可以在switch语句中使用find方法来获得所需的输出。
switch(varname){
case["afshin","saeed","larry"].find(name => name === varname):
alert("Hey")
break;
default:
alert('Default case');
break;
}