Javascript提示验证? [英] Javascript Prompt Validation?
本文介绍了Javascript提示验证?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想提示用户输入一项运动(棒球,足球,足球或赛道)。假设我输入高尔夫。在进入其中一项有效的运动之前,如何让它继续让我参加运动?这项运动决定了他们在哪个领域上演。以下是我的代码。
I want to prompt the user to enter a sport (baseball, football, soccer, or track). Let's say I enter "Golf". How do I get it to keep asking me to enter a sport until I enter one of the valid sports? The sport determines what field they play on. Below is my code.
var sport = prompt("What sport do you play? (Baseball, Football, Soccer, or Track)").toLowerCase ();
switch (sport) {
case "baseball":
field = "Field 1";
break;
case "football":
field = "Field 2";
break;
case "soccer":
field = "Field 3";
break;
case "track":
field = "Field 4";
break;
default: alert("Please enter a valid sport");
}
推荐答案
loop:
while(true){
var sport = prompt("What sport do you play? (Baseball, Football, Soccer, or Track)").toLowerCase();
switch (sport) {
case "baseball":
field = "Field 1";
break loop;
case "football":
field = "Field 2";
break loop;
case "soccer":
field = "Field 3";
break loop;
case "track":
field = "Field 4";
break loop;
default: alert("Please enter a valid sport");
}
}
或
var field;
while(true){
var sport = prompt("What sport do you play? (Baseball, Football, Soccer, or Track)").toLowerCase();
if(!sport || /^(baseball|football|soccer|track)$/.test(sport)){
field = "Field " + ("baseball|football|soccer|track".split("|").indexOf(sport)+1);
break;
}else{
alert("Please enter a valid sport");
}
}
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