How to print object array in JavaScript?

There is a wonderful print_r implementation for JavaScript in php.js library.

Note, you should also add echo support in the code.

DEMO: http://jsbin.com/esexiw/1

If you are using Chrome, you could also use

console.log( yourArray );

Simply stringify your object and assign it to the innerHTML of an element of your choice.

yourContainer.innerHTML = JSON.stringify(lineChartData);

If you want something prettier, do

yourContainer.innerHTML = JSON.stringify(lineChartData, null, 4);

var lineChartData = [{
            date: new Date(2009, 10, 2),
            value: 5
        }, {
            date: new Date(2009, 10, 25),
            value: 30
        }, {
            date: new Date(2009, 10, 26),
            value: 72,
            customBullet: "images/redstar.png"
        }];

document.getElementById("whereToPrint").innerHTML = JSON.stringify(lineChartData, null, 4);

<pre id="whereToPrint"></pre>

But if you just do this in order to debug, then you'd better use the console with console.log(lineChartData).

Did you check

console.table(yourArray);

More infos here: https://developer.mozilla.org/en-US/docs/Web/API/Console/table