Transform coordinates in a geojson from (long,lat) to (lat,long)

switchCoords.php

<?php  
    /*
    * Transform coordinates in a geojson from (long,lat) to (lat,long)
    *
    * TOOLS: geojsonlint.com to validate geojson
    */

    $file = file_get_contents("pipeline (1).geojson");
    $file = json_decode($file);

    for ($i = 0; $i < count($file->features); $i++){
        $coords = $file->features[$i]->geometry->coordinates;

        foreach($coords as $key=>$value){
            $coords[$key] = [$value[1], $value[0]];
        }

        $file->features[$i]->geometry->coordinates = $coords;
    }


    $f = json_encode($file);
    file_put_contents("pipeline_transform_1.geojson", $f);
    echo "done";