coffeescript-为什么总是将其输出为'1'？

Question

为什么即使randomArea不是North，它也总是输出为“ 1”？

if randomArea = "North"
    id.innerHTML = "1"
else if randomArea = "South"
    id.innerHTML = "2"
else if randomArea = "East"
    id.innerHTML = "3"
else if randomArea = "West"
    id.innerHTML = "4"
else if randomArea = "Central"
    id.innerHTML = "5"
else if randomArea = ""
    id.innerHTML = "6"

Answer 1

在JavaScript中，=是一个赋值运算符，它将始终分配该值，if语句将评估该值的真实性。在这种情况下，“ North”是一个非空字符串，这是事实，因此为id.innerHTML分配了其值"1"。应该使用等号运算符==代替。

if randomArea = "North"       // <-- here
    id.innerHTML = "1"
else if randomArea = "South"
    id.innerHTML = "2"
else if randomArea = "East"
    id.innerHTML = "3"
else if randomArea = "West"
    id.innerHTML = "4"
else if randomArea = "Central"
    id.innerHTML = "5"
else if randomArea = ""
    id.innerHTML = "6"

您需要更改所有相等条件以评估真实性，而不是分配值，该值始终使用非空字符串解析为true：

if randomArea == "North"            // <-- here
    id.innerHTML = "1"
else if randomArea == "South"       // <-- here
    id.innerHTML = "2"
else if randomArea == "East"        // <-- here
    id.innerHTML = "3"
else if randomArea == "West"        // <-- here
    id.innerHTML = "4"
else if randomArea == "Central"     // <-- here
    id.innerHTML = "5"
else if randomArea == ""            // <-- here
    id.innerHTML = "6"

注意：

• // <-- here最有可能需要为了有效的CoffeeScript而被删除