I have an array which looks like this :
selected_products[0]=["r1","7up",61,"Albertsons"]
selected_products[1]=["r3", "Arrowhead",78,"Arrowhead "]
selected_products[2]=["r8", "Betty Crocker Cake Mix (Variety)",109,"Arrowhead "]
...
how can I search for an item in this array according to the first entry in each item (r1,r2,..) the array is huge I am looking for a fast an effective way to get results from this array I used the JQuery function jQuery.inArray but it couldn't find any thing in my array , I used it this way :
alert($.inArray(["r1","7up",61,"Albertsons"],selected_products))// it returns -1
alert($.inArray("r1",selected_products))//this also returns -1
If you want it to be fast, you'll want a for
loop so that you can break the loop when the match is found.
var result;
for( var i = 0, len = selected_products.length; i < len; i++ ) {
if( selected_products[i][0] === 'r1' ) {
result = selected_products[i];
break;
}
}
Of course this assumes there's only one match.
If there's more than one, then you could use $.grep
if you want jQuery:
var result = $.grep(selected_products, function(v,i) {
return v[0] === 'r1';
});
This will give you a new Array that is a subset of the matched items.
In a similar manner, you could use Array.prototype.filter
, if you only support modern JavaScript environments.
var result = selected_products.filter(function(v,i) {
return v[0] === 'r1';
});
One other solution would be to create an object where the keys are the rn
items. This should give you a very fast lookup table.
var r_table = {};
for( var i = 0, len = selected_products.length; i < len; i++ ) {
r_table[selected_products[i][0]] = selected_products[i];
}
Then do your lookups like this:
r_table.r4;
Again this assumes that there are no duplicate rn
items.
So you are trying to find the index of the matched result?, well that changes the things a little bit:
var index=-1;
for(var i = 0, len = selected_products.length; i < len; i++){
if(selected_products[i][0] === "r1"){
index = i;
break;
}
}
if(index > -1){
alert(selected_products[index].join(","));//"r1,7up,61,Albertsons"
}
Note: This will return the first result matched, if you want to get an array containing a list of all indexes:
var results=[];
for(var i = 0, len = selected_products.length; i < len; i++){
if(selected_products[i][0] === "r1"){
results.push(i);
}
}
You can then call (for example) the last 'r1' matched like this selected_products[results[results.length-1]].join(",");
You might wanna consider not doing these things in Javascript but in a server sided language (PHP/Java/.NET). In this way you:
An example how to do this in PHP:
<?php
function search($array, $key, $value)
{
$results = array();
if (is_array($array))
{
if (isset($array[$key]) && $array[$key] == $value)
$results[] = $array;
foreach ($array as $subarray)
$results = array_merge($results, search($subarray, $key, $value));
}
return $results;
}
?>
Just to pick up @am not i am's great input. Here is a live example. He solved it. I just wanted to give an example that it works. Hope it helps. This puts the values found from the selected value in 2 input fields.
http://jsfiddle.net/asle/ZZ78j/2/
$(document).ready(function () {
var liste = [];
liste[0] = ["First Name", "12345678", "[email protected]"];
liste[1] = ["Second Name", "20505050", "second.nametestdomain.no"];
liste[2] = ["", "", ""];
$("#selger").change(function () {
var valg = ($(this).val());
var telefon;
var epost;
for (var i = 0, len = liste.length; i < len; i++) {
if (liste[i][0] === valg) {
telefon = liste[i][1];
epost = liste[i][2];
$("#tel").val(telefon);
$("#epost").val(epost);
break;
}
}
});
});
Try this,
// returns the index of inner array, if val matches in any array
function findIn2dArray(arr_2d, val){
var indexArr = $.map(arr_2d, function(arr, i) {
if($.inArray(val, arr) != -1) {
return 1;
}
return -1;
});
return indexArr.indexOf(1);
}
function test(){
alert(findIn2dArray(selected_products, 'r8'));
}
You may create index object { r1: 1, r2: 2,..., < search key >: < element index >, ...} and use it for searching.
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