jQuery全局变量可在任何地方使用

问题描述

我开始怀疑jquery易于使用且灵活.我有这个:

I am starting to doubt that jquery is easy to use and flexible.I have this:

var prodata=[];
var request = $.get("proDB.txt", function(data) {
    var lines=data.split(/\n/);
    var numberofmodels=lines.length-2;
    //var prodata=[];
    var i;
    prodata.push(0);
    var fieldnames=lines[0].split(/\t/);
    for (i = 1; i < lines.length-1; ++i) {
        var fields=lines[i].split(/\t/);
        prodata.push(i);
        var j;
        prodata[i]={};
        for (j = 0; j < fields.length; ++j) {
            //prodata[i][fieldnames[j]]=fields[j];
            var str=fieldnames[j];
            prodata[i][str]=fields[j];

        }
    }

    //FILL THE DROPDOWN LIST
    var options = '';
    for (i = 1; i < lines.length-1; ++i) {
        if (prodata[i]['name'].indexOf("elly") >= 0) {
            var iselected = i;
        }
        options += '<option label="bla" value="' + prodata[i]['id'] + '">' + prodata[i]['name']+', '+prodata[i]['brand']+', '+prodata[i]['model']+'</option>';
    }
    $("#userchosenpromodel").html(options);
    //SELECT DEFAULT OPTION
    $('#userchosenpromodel option[value="' + prodata[iselected]['id'] + '"]').attr("selected", "selected");
}, 'text'); //$.get

在这样定义之后，我想在代码的下面使用proId:

I would like to use proId, lower in my code, after it's been defined like that:

//SUBMIT FORM
$('#submitbutton').click(function(e) {
    e.preventDefault();
    request.done(function(){
        proId=$('#userchosenpromodel option[selected="selected"]').val();
        proId=parseInt(proId);
        computeUserDimensions(prodata[proId]);
    });
});
    console.log(proId);

如何?

与prodata相同的问题...我有request.done我无法摆脱

Same problem for prodata...I have request.done that I can't get rid of

谢谢

推荐答案

您对jQuery没问题，但基于异步/事件的逻辑却没有问题.

You don't have a problem with jQuery but with asynchronous/event based logic.

您不能同步使用异步函数的返回值.您必须在回调或从回调中调用的函数中使用结果:

You can't synchronously use the return of an asynchronous function. You must use the result in the callback or in a function you call from the callback :

request.done(function(){
    var proId=$('#userchosenpromodel option[selected="selected"]').val();
    console.log(proId);
});

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