javascript for循环使用变量

Question

Can I use variable to do the second for loop so it list out all data in GroupA1 and GroupB1.

Tried but fail.. anyone have idea how to make it work?

for example

function Loop(){
    var AllGroup=["GroupA1","GroupB1"]
    var GroupA1=["A1","A2"]
    var GroupB1=["B1","B2"]
    var Group=""

for(var i = 0; i < AllGroup.length; i++){
    Group=AllGroup[i]

    var SubGroup=""
    for(var x = 0; x < Group.length; x++){
        SubGroup=Group[x]
        alert(SubGroup);
    }
}
}

Answer 1

Hopefully my sample code can help you to deal with your question

For example

<script>
    var GroupA1=["A1","A2"]
    var GroupB1=["B1","B2"]
    var Group=""
    var AllGroup = [GroupA1, GroupB1]    
for(var i = 0; i < AllGroup.length; i++){
    Group=AllGroup[i]

    var SubGroup=""
    for(var x = 0; x < Group.length; x++){
        SubGroup=Group[x]
        alert(SubGroup);
    }
}
</script> 

Answer 2

Do it this way:

function loop(){
 var GroupA1=["A1","A2"]
    var GroupB1=["B1","B2"]
var AllGroup=[GroupA1,GroupB1]

    var Group=""

    for(var i = 0; i < AllGroup.length; i++){
        Group=AllGroup[i]

        var SubGroup=""
        for(var x = 0; x < Group.length; x++){
            SubGroup=Group[x]
            alert(SubGroup);
        }
    }
}

Declare the arrays first then use them as objects in the next array.

Answer 3

This is the structure I would recommend, which is more logical, instead of what you're using.

function Loop(){
    //The object AllGroups contains all the other groups
    var AllGroups = { 
        "GroupA1": ["A1","A2"],
        "GroupB1": ["B1","B2"]
    };

    for(var group in AllGroups){
            if(AllGroups.hasOwnProperty(group)){
                //Access each group in AllGroups
                for(var i = 0; i < AllGroups[group].length; i++){
                    console.log(AllGroups[group][i]); //A1, A2, B1, B2
                }
            }
    }
}

Answer 4

Rearrange code like this so that AllGroup is a collection containing GroupA1 and GroupB1:

function Loop() {
    var GroupA1=["A1", "A2"];
    var GroupB1=["B1", "B2"];
    var AllGroup=[GroupA1, GroupB1];
    var Group = null;

    for(var i = 0; i < AllGroup.length; i++){
        Group = AllGroup[i];

        var SubGroup = "";
        for(var x = 0; x < Group.length; x++){
            SubGroup = Group[x];
            alert(SubGroup);
        }
    }
}

Before you were referencing the strings "GroupA1" "GroupB1" not the actual data contained in the subgroups that you create.