PHP add arraylist to existing array - php

Question

I am trying to encode the data in below JSON format. Not able to add the category array inside the categories. Scratching my head for long.. can anyone help me on this?
Desired Output:
{
"chart": {
"caption": "Product-wise Quarterly Revenue vs. Profit %",
"subCaption": "Harry's SuperMart - Last Year",
"xAxisname": "Quarter",
"pYAxisName": "Sales",
"sYAxisName": "Profit %",
"numberPrefix": "$",
"sNumberSuffix": "%",
"sYAxisMaxValue": "25",
"paletteColors": "#0075c2,#1aaf5d,#f2c500",
"bgColor": "#ffffff",
"borderAlpha": "20",
"showCanvasBorder": "0",
"usePlotGradientColor": "0",
"plotBorderAlpha": "10",
"legendBorderAlpha": "0",
"legendShadow": "0",
"legendBgAlpha": "0",
"valueFontColor": "#ffffff",
"showXAxisLine": "1",
"xAxisLineColor": "#999999",
"divlineColor": "#999999",
"divLineIsDashed": "1",
"showAlternateHGridColor": "0",
"subcaptionFontBold": "0",
"subcaptionFontSize": "14",
"showHoverEffect": "1"
},
"categories": [
{
"category": [
{
"label": "Q1"
},
{
"label": "Q2"
},
{
"label": "Q3"
},
{
"label": "Q4"
}
]
}
]
}
My PHP code:
$arrData = array(
"chart" => array(
"caption"=> "Product-wise Quarterly Revenue vs. Profit %",
"subCaption"=> "Harry's SuperMart - Last Year",
"xAxisname"=> "Quarter",
"pYAxisName"=> "Sales",
"sYAxisName"=> "Profit %",
"numberPrefix"=> "$",
"sNumberSuffix"=> "%",
"sYAxisMaxValue"=> "25",
"paletteColors"=> "#0075c2,#1aaf5d,#f2c500",
"bgColor"=> "#ffffff",
"borderAlpha"=> "20",
"showCanvasBorder"=> "0",
"usePlotGradientColor"=> "0",
"plotBorderAlpha"=> "10",
"legendBorderAlpha"=> "0",
"legendShadow"=> "0",
"legendBgAlpha"=> "0",
"valueFontColor"=> "#ffffff",
"showXAxisLine"=> "1",
"xAxisLineColor"=> "#999999",
"divlineColor"=> "#999999",
"divLineIsDashed"=> "1",
"showAlternateHGridColor"=> "0",
"subcaptionFontBold"=> "0",
"subcaptionFontSize"=> "14",
"showHoverEffect"=> "1"
)
);
$arrData["categories"] = array();
$arrData["category"] = array();
//array_push($arrData["categories"],array( $arrData["category"]));
//array_push($arrData["categories"],array( $arrData["category"]));
array_push($arrData["category"], array(
"label" => "Q1",
));
array_push($arrData["category"], array(
"label" => "Q2",
));
$json_string = json_encode($arrData, JSON_PRETTY_PRINT);
echo $json_string;
}
PHP output:
{
"chart": {
"caption": "Product-wise Quarterly Revenue vs. Profit %",
"subCaption": "Harry's SuperMart - Last Year",
"xAxisname": "Quarter",
"pYAxisName": "Sales",
"sYAxisName": "Profit %",
"numberPrefix": "$",
"sNumberSuffix": "%",
"sYAxisMaxValue": "25",
"paletteColors": "#0075c2,#1aaf5d,#f2c500",
"bgColor": "#ffffff",
"borderAlpha": "20",
"showCanvasBorder": "0",
"usePlotGradientColor": "0",
"plotBorderAlpha": "10",
"legendBorderAlpha": "0",
"legendShadow": "0",
"legendBgAlpha": "0",
"valueFontColor": "#ffffff",
"showXAxisLine": "1",
"xAxisLineColor": "#999999",
"divlineColor": "#999999",
"divLineIsDashed": "1",
"showAlternateHGridColor": "0",
"subcaptionFontBold": "0",
"subcaptionFontSize": "14",
"showHoverEffect": "1"
},
"categories": [
],
"category": [
{
"label": "Q1"
},
{
"label": "Q2"
}
]
}

Answer 1

for ($i = 1; $i <= 4; $i++) {
$arrData['categories'][0]['category'] []= ["label" => "Q{$i}"];
}
By the way, you should use []= instead of array_push, because in that way there is no overhead of calling a function.