Question

我想动态生成一个整数（在下面的情况下为100或500）并使用它来访问单独的数组。在后面的步骤（不是下面代码的一部分）中，我还想以相同的方式访问这些数组的不同部分（“消息1,2或3”）。

对于这个概念证明，我没有动态生成整数，但我只是将它设置为100。

然后我尝试使用eval()动态生成由“warning”和100组成的数组名称，但它无法正常工作。

这是我的代码：

// two arrays are defined, warning100 and warning500
var warning100 = [
    { "message1":"Ok, go ahead and start typing!" },
    { "message2":"Keep going!" },
    { "message3":"You can do it!" }
];

var warning500 = [
    { "message1":"Slow down..." },
    { "message2":"That's it!" },
    { "message3":"Maximum reached." }
];

// set i to 100 and h to 1 for testing purposes, will be random integers in the final version
var i = 100;
var h = 2;
// create variable names as a combination of a string and i or h
// those variables will be used to access one of the arrays from above and one of the messages;
eval("var warningNumber = warning" + i + ";");
eval("var messageNumber = message" + h + ";");

/* alternative code for creating the two variable values
var warningNumber = "warning" + i;
var messageNumber = "message" + h;
*/

// the variable warningNumber from above is now used again to access the array warning100
// the varaible messageNumber is used to access one of the messages
// within that array message1 should be displayed
// create variable to be used in the document.write below
var warning = warningNumber[0].messageNumber;

// should alert "Ok, go ahead and start typing!"    
alert(warning);

Answer 1

为什么不将每组警告都作为warningNumber对象的一部分？这样你可以做到

var warnings = {100: { 1:"Ok, go ahead and start typing!",
                       2:"Keep going!",
                       3:"You can do it!"
                     },
                500: { 1:"Slow down...",
                       2:"That's it!",
                       3:"Maximum reached."
                     }
               };
alert(warnings[i][h]);

这样，所有的评估都不需要完成。

Answer 2

为什么不将它包装在一个物体中？

var dynamicHolder = {};
var i = 100;
var h = 2;
dynamicHolder["warningNumber"] = "warning" + i;
dynamicHolder["messageNumber"] = "message" + h;

Answer 3

试试这个：

var warnings = {

    warning100: {
        "message1":"Ok, go ahead and start typing!",
        "message2":"Keep going!",
        "message3":"You can do it!"
    },
    warning500: {
        "message1":"Slow down...",
        "message2":"That's it!",
        "message3":"Maximum reached."
    }
}

var i = 100;
console.log( warnings["warning" + i] );
i += 400;
console.log( warnings["warning" + i] );

console.log( warnings["warning" + i ]["message1"] );

Example

动态javascript变量

3 个答案: