如何在 javascript 中创建布尔表达式并使用 alert() 生成消息？

Question

我正在 JavaScript 中编写一个程序，告诉用户他们是否在比赛中获胜。条件是：女生记录20秒，男生记录15秒抢跑时间小于 0.50 秒，如果参赛者抢跑，那么他们就没有获胜。我必须使用 prompt() 命令来询问他们是参加男孩还是女孩比赛，然后询问他们的分数和反应时间。编写一个布尔表达式并使用 alert() 命令创建一条消息，告诉他们是否赢了。当询问用户参加哪个项目时，可接受的答案是 “男孩”或“女孩”。到目前为止我有这个，但我不认为它是完全正确的。

var boysRecord = 15;
var girlsRecord = 20;
var falseStart = 0. 50;
var event = prompt("Are you competing in the boys or girls event?");
if (event == "boys" || "girls");
var score = prompt("What is your score?");
 } else {
var event = prompt("Are you competing in the boys or girls event?");
var reactionTime = prompt("What is your reaction time?");
if 
 (event == "boys"; && score > 15; && reactionTime >= 0.5);
{ alert(" You have won");
} else if {
(event = "girls"; && score > 20; && reactionTime >= 0.5);
{ alert(" You have won");
}
else {
    alert(" You have lost");
}

Answer 1

首先，我建议您缩进代码。它更易于阅读并帮助您跟踪括号。

您有一些错误。您缺少一些括号并且分号太多。

下面是应该有效的代码：

var boysRecord = 15;
var girlsRecord = 20;
var falseStart = 0.50;
var event = prompt("Are you competing in the boys or girls event?");
if (event == "boys" || "girls"){
    var score = prompt("What is your score?");
} else {
    event = prompt("Are you competing in the boys or girls event?")
}
var reactionTime = prompt("What is your reaction time?");
if(event == "boys" && score > 15 && reactionTime >= 0.5){
    alert(" You have won");
} else if(event = "girls" && score > 20 && reactionTime >= 0.5){
    alert(" You have won");
} else {
    alert(" You have lost");
}

Answer 2

首先，正如 Carlos 提到的，您的代码一团糟。

我猜你正试图做这样的事情。 https://jsfiddle.net/wpjuzjae/8/

注意：在编写第二行之前，请确保第一行有效。复制粘贴代码块并不总是有效。

祝你好运

var boysRecord = 15;
var girlsRecord = 20;
var falseStart = 0.50;
var score = 0;
var event = prompt("Are you competing in the boys or girls event?");
while (event != "boys" && event != "girls") {
  event = prompt("Are you competing in the boys or girls event?");
}

var score = prompt("What is your score?");
var reactionTime = prompt("What is your reaction time?");

if (event == "boys" && score > 15 && reactionTime >= 0.5) {
  alert(" You have won");
} else if (event = "girls" && score > 20 && reactionTime >= 0.5) {
  alert(" You have won");
} else {
  alert(" You have lost");
}

如何在 javascript 中创建布尔表达式并使用 alert() 生成消息？

How to create boolean expression in javascript and generate a message using alert()?

javascript

alert

boolean

prompt