Home / Questions / 159218
Accepted
Ándres Felipe Patiño
Asked: 2020-04-26 11:52:54 +0800 CST 2020-04-26 11:52:54 +0800 CST

How to loop through a php array in javascript?

  • 772

I'm using laravel for a project, I have the following problem, in the controller I have an array called escalaphonevalue that is filled, then that array was sent to the view using return and compact, in the view I need to pass that array to a script and go through it inside javascript, I pass the php array to the script as follows in the blade view:

<script>
var cont= "<?php echo $count;  ?>";
for (var index1 = 0; index1 < cont; index1++) {

        precioesca[index1]="<?php echo $escalafonvalor[".index1."] ?>";        


        alert(precioesca[index1]);

    }
</script>

the array arrives like this:

array:3 [▼
  0 => 13282000
  1 => 4688000
  2 => 2344000
]

The array passes correctly to the script, since if I give it index 0 it shows me its value and saves it in the js variable. My problem comes when I try to go through the array with the variable index1 of the javascript for, since it tells me that the variable index1 is undefined:

enter image description here

What can be wrong here? or how should it be done?

php

4 Answers

  1. In this case the variable index1 is a variable in javascript, but you try to access it in php. The correct way to do it would be:

    <script>
var precioesca = [];
var escalafon = <?php echo json_encode($escalafonvalor);  ?>;
var newEscalafon = JSON.parse(escalafon);

newEscalafon.forEach(function(value, index) {
    precioesca[index] = value;
    alert(precioesca[index]);
});
</script>
    • 3

  2. Consider that the code PHPis compiled and executed on the server side, instead JSit is compiled and executed on the client side ( usually a browser ).

    In other words, the code is executed first PHP, the result is returned to the client, and the client executesJS .

    Taking this into account, if you need to iterate through JSinformation stored in a variable PHP, what you have to do is print with PHPsaid information so that it becomes visible inJS

    Solution:

    You can use the function json_encode, which allows you to convert the value of the variable to an object that you JScan process.

    Example:

    <script>
var precioesca = [];
var escalafon = <?php echo json_encode((array) $escalafonvalor);  ?>;

escalafon.forEach(function(value, index) {
    precioesca[index] = value;
    alert(precioesca[index]);
});
</script>

    PS: The expression will (array) $escalafonvalorconvert ( in the case that it was not ) $escalafonvalorinto an array, thus allowing the correct iteration with JS.

    • 3

  3. You can do it in the following way using length, which makes it take the total length of the array and translate it into for as index < 10an example.

    <script>
var cont= "<?php echo $count;  ?>";
for (var index1 = 0; index1 < cont.length; index1++) {  
        alert(cont[index1]);

    }
</script>

    I leave you an executable example so you can see it in action.

     
    var cont = ["valor1",2,3,4,"valor3","texto",2,4];
    for (var index1 = 0; index1 < cont.length; index1++) {  
            console.log(cont[index1]);

    }

    • 1
  4. Best Answer

    Using the information that Marcos gave me, I used it in this way, I attach my code in case it helps someone.

    var precioesca = [];
    var escalafon = "<?php echo json_encode($escalafonvalor); ?>";

    precioesca=JSON.parse(escalafon);


    for (var index = 0; index < precioesca.length; index++) {

        alert(precioesca[index]);
    }
    • 0