Stripping last comma from PHP foreach loop
Question
I'm wondering how I can remove the trailing comma in this foreach loop in my PHP script running inside of javascript.
<html>
<head>
<script type='text/javascript' src='https://www.google.com/jsapi'></script>
<script type='text/javascript'>
google.load('visualization', '1', {'packages': ['geochart']});
google.setOnLoadCallback(drawRegionsMap);
function drawRegionsMap() {
var data = google.visualization.arrayToDataTable([
['Country','Blocks'],
<?php
foreach ($bans as $key => $value)
print"['$key', $value],\n";
?>
]);
var options = {
backgroundColor : '#555555',
colors : ['#FFFF00', '#FF0000']
};
var chart = new google.visualization.GeoChart(document.getElementById('chart_div'));
chart.draw(data, options);
};
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
This causes a problem as I get a trailing comma, I've tried an implode method and rtrim method but none of those appear to be working (I've also never used those functions so I may be doing it wrong)
My implode method was:
<?php
$resultstr = array();
foreach ($bans as $key => $value)
print"['$key', $value],\n";
$resultstr = implode(",", $resultstr);
?>
My rtrim method was:
<?php
$resultstr = array();
foreach ($bans as $key => $value)
print"['$key', $value],\n";
echo rtrim($resultstr, ",");
?>
When compiled it looks like this:
<html>
google.load('visualization', '1', {'packages': ['geochart']});
google.setOnLoadCallback(drawRegionsMap);
function drawRegionsMap() {
var data = google.visualization.arrayToDataTable([
['Country','Blocks'],
['Japan', 11],
['United States', 45],
['Argentina', 1],
]);
var options = {
backgroundColor : '#555555',
colors : ['#FFFF00', '#FF0000']
};
var chart = new google.visualization.GeoChart(document.getElementById('chart_div'));
chart.draw(data, options);
};
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
4 answers
solution1
6 ACCPTED
What you should do instead of trimming the string afterwards is not generating the trailing comma at all:
$not_first = false;
foreach ($bans as $key => $value) {
if ($not_first) {
print(", ");
}
$not_first = true;
print "['$key', $value]\n";
}
solution2
4 2012-11-26 19:25:53
This could be another approach:
var data = google.visualization.arrayToDataTable(<?php
$table = array(array('Country', 'Blocks'));
foreach($bans as $key => $value) {
$table[] = array($key, $value);
}
echo json_encode($table);
?>);
I often use json_encode so I don't have to take care of escaping all the values.
solution3
2 2012-11-26 19:16:20
You missed something:
echo rtrim($resultstr, ",");
You could also do:
echo substr($resultstr, 0, -1);
solution4
0 2012-11-26 19:28:09
You could create an array that contains the [key, value] pieces and then glue them with implode :
PHP
<?php
$arr = array();
$arr['key1'] = 'val1';
$arr['key2'] = 'val2';
$arr['key3'] = 'val3';
function PrepareValues(&$item, $key) {
$item = "['$key', $item]";
}
array_walk_recursive($arr, "PrepareValues");
$resultstr = implode(",\n", $arr);
print($resultstr);
?>
Output
['key1', val1],
['key2', val2],
['key3', val3]
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