I am looking for a solution to create a single multidimensional associate array in javascript.
What I have: I have a mysql database I am accessing with php and have an array containing all fields (key,value pairs) in a single record. Their are upwards of 30 fields in each record so I am looking for a dynamic solution. In the html coding, there is a form that is used to update a specific record in the table. I am using a function call on each input to fill a javascript array by key and value. The keys are identical to the keys in the php array. In the function I am doing a json_encode call on the php array to pull in the "old" data to make it accessible to javascript.
What works: I am able to create a dynamic javascript associate array from the new data coming from the input function calls. I have tested this out using an alert after each call to the function.
What I need: A method to change the javascript array to a multidimensional array, pulling in the old value and adding it to the new array tied to the original key.
This works:
var changes={};
function change(key,value) {
changes[key[value]]=value;
for (key in changes) {
alert('key: '+key+'... value: '+changes[key]);
}
}
this is along the lines of what I am looking for:
var changes={};
function change(key,value) {
var oldInfo = eval(<? echo json_encode($oldInfo); ?>); //this from the php array
changes[key[newValue]]=value;
changes[key[oldValue]]=oldInfo[key];
for (key in changes) {
alert('key: '+key+'... value: '+changes[key[newValue]]);
}
}
Can someone point me in the right direction?
To clarify:
My php array $oldInfo
holds the old information from the table, for example:
{fName=>"charles",lName=>"madison", etc.}
The javascript array hold new information:
{fName=>"Charlie",lName=>"Madison", etc.}
I would like a new multidimentional array (PHP) (or object in JavaScript) that would look something like this:
{fName=>{"charles","Charlie"}, lName=>{"madison","Madison"}, etc.}
lName and fName would be the key fields that are synonymous to both the PHP array and the JavaScript object.
It's really unclear what you want, but there are a couple of serious flaws with your logic:
var changes={}; ///this one way of declaring array in javascript
No, it isn't. That's an Object, which is very different from an array.
eval(<? echo json_encode($oldInfo); ?>);
You don't need eval
here. The output of json_encode
is JSON, which is a subset of JavaScript that can simply be executed.
changes[key[value]]=value;
This is totally wrong, and still a single-dimensional array. Assuming key
is an array, all you're doing is inverting the keys/values into a new array. If key looks like this before...
'a' => 1 'b' => 2 'c' => 3
... then changes
will look like this after:
1 => 'a' 2 => 'b' 3 => 'c'
For a multidimensional array, you need two keys. You'd write something like changes[key1][key2] = value
.
Your variable naming is wrong. You should never see a line that reads like this: key[value]
. That's backwards. The key goes between the []
, the value goes on the other side of the =
. It should read something like array[key] = value
.
RE: Your clarification:
This doesn't work: {fName=>{"charles","Charlie"},...}
. You're confusing arrays and objects; Arrays use square brackets and implicit numeric keys ( ["charles", "Charlie"]
for example) while Objects can be treated like associative arrays with {key1: "value1", key2: "value2"}
syntax.
You want an array, where each key is the name of a property and each value is an array containing the old and new values.
I think what you want is actually quite simple, assuming the "value" you're passing into the function is the new value.
var changes = {};
var oldInfo = <?= json_encode($oldInfo) ?>;
function change(key, value) {
changes[key] = [ oldInfo[key], value ]
}
This :
changes[key[newValue]]
Should be:
changes[key][newValue]
What I need: A method to change the javascript array to a multidimensional array, pulling in the old value and adding it to the new array tied to the original key.
Use aliases for the numeric indices to do this:
var foo = ["Joe","Blow"];
var bar = ["joe","blow"];
var names = {};
foo.fname = foo[0];
bar.fname = bar[0];
foo.lname = foo[1];
bar.lname = bar[1];
names.fname = [foo.fname,bar.fname];
names.lname = [foo.lname,bar.lname];
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