Equating JS variable to json encoded php array value regardless of index

Question

I'm comparing a JS variable to a json encoded php array value, which is working currently as is:

function myFunction() {
    var itemArray = <?php echo json_encode($items);?>;   
    console.log(itemArray);

    var number = 14;

    if(number == itemArray[0]['number']){
        success.style.display = "block";
        error.style.display = "none";
    }
}

[{
    0:
        name: "nameOne"
        number: 14
    1:
        name: "nameTwo"
        number: 13
    2:
        name: "nameThree"
        number: 8
}]

$items: array:3 [
    0=>array{
        name: "nameOne"
        number: 14
    }
    1=>array{
        name: "nameTwo"
        number: 13

    }
    2=>array{
        name: "nameThree"
        number: 8
    }
]

So It's indexed to zero which is fine for testing the comparison, but this isn't what I want. I want to be able to look at the 'number' field of every index in this object. So basically I want to say "If 14 exists as 'Number' in any of the indeces here, then this should be true".

I want to do this for other fields eventually too, but when I change my index to if(number == itemArray[]['number']){ then it says the function is undefined.

How can I do this for any index in the object to look at that field?

Answer 1

If you just want to array an array of objects that match the key try this. The 2nd function returns an array of the matching indices, although there is probably a better way to do that.

 var array = [{ name: "nameOne", number: 14 },{ name: "nameTwo", number: 13 },{ name: "nameThree", number: 8 },{ name: "nameThree", number: 14 } ]; function findMatches(array, key, value) { return array.filter(item => item[key] == value); } function findIndex(array, key, value) { return array.map((item,index) => item[key] === value ? index : undefined).filter(x => x !== undefined); } console.log(findMatches(array, "number", 14)); console.log(findIndex(array, "number", 14)); console.log(findMatches(array, "number", 13)); console.log(findIndex(array, "number", 13)); console.log(findMatches(array, "number", 2)); console.log(findIndex(array, "number", 2)); 

Answer 2

<?php
//I suppose Your items will be like
$items = 
array(array("name" => "nameOne","number" => 14),
    array("name"=> "nameTwo","number"=> 13),
     array("name"=> "nameThree","number"=> 8)
);

echo "<pre>";
print_r($items);
?>

<script>
myFunction();
function myFunction() {
  //Use the JavaScript function JSON.parse() to convert text into a JavaScript object:
   var json  = JSON.parse('<?php echo json_encode($items);?>');   
   console.log(json );

   var number = 14;
   var result = false;
   var error = '';
   //Use the loop to get the value from json
  for(var i = 0; i < json.length; i++) {
    var obj = json[i];

   //If obj.number is 14 add your code
   if(number == obj.number){
      result = true;

   }
  }

 if(result){
    alert('success message');
    success.style.display = "block";
    error.style.display = "none";
 }else{
    success.style.display = "none";
    error.style.display = "block";
 }

}
</script>