Question

＆＃34;修改汽车绘画示例，以便在您拥有自己喜欢的颜色的情况下为汽车涂上颜色;否则它是用你车库的颜色绘制的（如果颜色已知）;否则它被涂成红色。＆＃34; 汽车绘画示例： car.color = favoriteColor || ＆＃34;黑色＆＃34 ;;

如何或如何才能使我的脚本有效？

car.color = favoriteColor || "red";
if (car.color = favoriteColor ){ 
    alert("your car is " + favoriteColor);

} else if (car.color = garageColor){
    alert("your car is " + garageColor);

} else {
    car.color = "red";
}

Answer 1

这是您问题的正确答案：

请参阅我的评论，以便更好地了解其工作原理。

if (favoriteColor) {
  car.color = favoriteColor; // If you have a favorite color, choose the favorite color.
} else if (garageColor) {
  car.color = garageColor;   // If the garage color is known, choose the garage color.
} else {
  car.color = 'red';         // Otherwise, choose the color 'red'.
}

alert('Your car is: ' + car.color);

<强> Try it Online!

相关问题（进一步深入了解）：

https://softwareengineering.stackexchange.com/q/289475

替代方法：

作为另一种可能性，您可以编写conditional (ternary) operation将所有逻辑压缩为单个语句。

alert('Your car is: ' + (car.color = favoriteColor ? favoriteColor : garageColor ? garageColor : 'red'));

Answer 2

看起来你需要在if语句中使用double equals符号。检查相等性时使用==。试试这个：

car.color = favoriteColor || "red";
if (car.color == favoriteColor ){ 
    alert("your car is " + favoriteColor);

} else if (car.color == garageColor){
    alert("your car is " + garageColor);

} else {
    car.color = "red";
}

Answer 3

希望这段代码有用

function _showFavColor(getColor){
 var favoriteColor = 'red';
 var garageColor  ="blue";   
 var carColor = getColor;

if (carColor == favoriteColor ){ 
    alert("your car is " + favoriteColor);

} else if (carColor == garageColor){
    alert("your car is " + garageColor);

} else {
    carColor = "red";
}
}
_showFavColor('red');
_showFavColor('blue');

jsfiddle

还要注意如何在js中完成等式检查。您可以关注此链接或谷歌 Which equals operator (== vs ===) should be used in JavaScript comparisons?

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Equality_comparisons_and_sameness

此外，如果您使用car.color，如果不创建汽车对象，则会抛出错误

 'Uncaught SyntaxError: Unexpected token . '

初学者JavaScript - 汽车颜色

3 个答案: