[Solved]-how to enable drawing multiple lines on highstock basic-line graph?-Highcharts

right now you have:

                    series : [{
                        name : 'total market',
                        data : arr,
                        tooltip: {
                            valuedecimals: 2
                        }
                    }]

so you have just one object inside series. if you want multiple series then should be something like that:

                    series : [{
                        name : 'total market i',
                        data : arr_1,
                        tooltip: {
                            valuedecimals: 2
                        }
                    },{
                        name : 'total market ii',
                        data : arr_2,
                        tooltip: {
                            valuedecimals: 2
                        }
                    }]

edit:

to add multiple series, push them to array:

var myseries = [];

myseries.push({
    name : 'total market i',
    data : arr_1
});
myseries.push({
    name : 'total market ii',
    data : arr_2
});
myseries.push({
    name : 'total market iii',
    data : arr_3
});

then create chart:

series: myseries