我想在 js 中更改 var 颜色。怎么了？

Question

我想将 var 颜色更改为蓝色。蓝变红。和红色到绿色。你能帮我吗？谢谢...

function ColorChange() {
        var color = green;
        if color == "green" {
        var color = blue;
        }
        else if color == blue {
        var color = red;
        }
        else {
        var color = green;
        }
}

Answer 1

function ColorChange(color) {
    if (color == "green") {
        color = "blue";
    }
    else if (color == "blue") {
       color = "red";
    }
    else {
       color = "green";
    }
return color;

}

Answer 2

您的代码中有多个语法错误。考虑以下修订：

function ColorChange() {
    var color = "green";
    if(color == "green"){
        color = "blue";
    }
    else if(color == "blue"){
        color = "red";
    }
    else{
        color = "green";
    }
}

此外，如果您手动设置 var color = "green"; 那么如果您的 if 块，其中 none 将 ever return true。如果您尝试根据其值调用此函数时更改全局变量，则它可能看起来像这样：

var color = "green";

...

function ColorChange() {
    if(color == "green"){
        color = "blue";
    }
    else if(color == "blue"){
        color = "red";
    }
    else{
        color = "green";
    }
}

如果您希望此函数接受 string 颜色和 return 排列结果，请考虑如下：

function ColorChange(color) {
    if(color == "green"){
        color = "blue";
    }
    else if(color == "blue"){
        color = "red";
    }
    else{
        color = "green";
    }
    return color;
}

总的来说，您可能是 JavaScript 的新手，您可能需要考虑 beginner tutorial to get familiar with the syntax

我想在 js 中更改 var 颜色。怎么了？

I want change var color in js. What is wrong?

javascript

var