Question

这是我在Stack Overflow上的第一个问题，也是我遇到问题的第一个问题。

＆＃13;

    var room = "ballroom";
    var suspect = "Mr. Kalehoff";
    
    var weapon = "";
    var solved = true;
    
    if (room === "dining room" && suspect === "Mr. Parkes") {
        weapon === "knife";
        solved === true;
    } else if (room === "gallery") {
        weapon === "trophy";
        solved === true;
    } else if (room === "ballroom" && suspect === "Mr. Kalehoff") {
        weapon === "pool stick";
        solved === true;
    } else {
        weapon === "poison";
        solved === false;
    }
    
    if (solved) {
    	console.log(suspect + " did it in the " + room + " with the " + weapon + "!");
    }

＆＃13;

在上面的javascript代码中，变量武器和已解决的值不会保存并反映在控制台上，即使我已经改变房间和怀疑符合条件;声明不会起作用。

对此有任何帮助将不胜感激。希望这一切都有道理。干杯！

Answer 1

if＆amp; amp;否则你需要使用单=

分配值

＆＃13;

var room = "ballroom";
var suspect = "Mr. Kalehoff";

var weapon = "";
var solved = true;

if (room === "dining room" && suspect === "Mr. Parkes") {
  weapon = "knife"; //changed here
  solved = true;    //changed here
} else if (room === "gallery") {
  weapon = "trophy";   //changed here
  solved = true;       //changed here
} else if (room === "ballroom" && suspect === "Mr. Kalehoff") {
  weapon = "pool stick";   //changed here
  solved = true;           //changed here
} else {
  weapon = "poison";       //changed here
  solved = false;          //changed here
}

if (solved) {
  console.log(suspect + " did it in the " + room + " with the " + weapon + "!");
}

＆＃13;

Answer 2

对于变量的赋值操作（或保存）值，必须使用single = symbol。
有关分配操作的更多参考
1.w3schools

2.developer.mozilla

所以使用

weapon = "knife";
solved = true;

Answer 3

else if中的变量“weapon”和“solve”只需要使用1'='。像这样：

weapon = "knife";
solved = true;

仅使用1'='将变量（武器）设置为新值（刀）。使用3'==='是要求它等于它的值和类型。换句话说，你在做的是询问“武器”是否匹配“刀”，这将输出“假”。 ===表示专门匹配TYPE和VALUE，而不仅仅是值。而==只会比较值，所以“1”== 1会输出'true'，因为javascript只是比较值，即使一个是字符串而一个是数字。但是===比较值和类型，所以“1”=== 1会输出'false'，因为即使值相同，类型也不同（一个是字符串，一个是数字）

请参阅Udacity / Grow With Google第11.19课 - 平等。

Udacity Murder Mystery - javascript不保存变量

3 个答案: