access arbitrary property from object

Question

I have a set of nesting json object like this:

var obj = {
  name: "student",
  contact: {
     phone: "22222",
     fax: "33333",
     ...
  },
  ...
}

And I have these text fields:

<input type="text" name="name" />
<input type="text" name="contact_phone" />
<input type="text" name="contact_fax" />
...

Now I want to fill these fields with appropriate property from above object. My question is how can I access anonymous property from that object? For example suppose I have this jquery code:

 $("#formID").find("input").each(function(index) {
    fieldName = $(this).attr("name");
    var namePart = fieldName.split("_");
    //I want something like this: console.log(obj.namePart[0].namePart[1])
});

Answer 1

Use obj["propertyName"]

obj[namePart[0]][namePart[1]]

---

$('#formID').find("input").each(function(index) {
    fieldName = $(this).attr("name");
    var namePart;
    if(fieldName.indexOf('_') > -1){
        namePart = fieldName.split("_");
        console.log(obj[namePart[0]][namePart[1]])
    }
    else{
        namePart = fieldName;
        console.log(obj[namePart])
    }

});

*Note: The property is not anonymous. If your run obj["propertyName"] on an object with no such property it will return undefined.

Answer 2

Edit: Sorry about that I misunderstood the question. What you are looking for is something like this.

var obj = {
    name: "student",
    contact: {
        phone: "22222",
        fax: "33333"
    }
};

$('#formID').("input").each(function(index) {
    fieldName = $(this).attr("name");
    var namePart = fieldName.split("_");

    var arbitraryVal = obj;
    for (var part in namePart) {
        if (arbitraryVal.hasOwnProperty(namePart[part])) {
            arbitraryVal = arbitraryVal[namePart[part]];
            continue;
        }
        arbitraryVal = null;
        break;
    }

    if (typeof $(this).val(arbitraryVal) !== 'undefined') {
        $(this).val(arbitraryVal);
    }
});

recusivly searches an object for each name part. If the name part is contact_phone It will look for obj.contact.phone if it is something_else_with_lots_of_underscores it will look for obj.something.else.with.lots.of.underscores

JS FIDDLE

Answer 3

    <form ID="formID">
        <input type="text" name="name" />
        <input type="text" name="contact_phone" />
        <input type="text" name="contact_fax" />
    </form>  

    $("#formID").find("input").each(function() {
        fieldName = $(this).attr("name");
        namePart = fieldName.split("_");
         if(namePart.length ==1 && namePart[0]=="name"){
             $(this).val(obj.name);
         }
         else if(namePart.length>1){
             $(this).val(obj[namePart[0]][namePart[1]]);
         }
        //I want something like this: console.log(obj.namePart[0].namePart[1])
    });      

http://jsfiddle.net/57vL6b0w/