I want to create an array by extracting the dates of some other array and then comma separate the values into a string.
array.push({date:created_at,username:user});
for (i in array) {
var combined=new array();
combined = array[i].date;
}
console.log(combined);
I am new to javascript and hard to follow in arrays.Thanks !! Can anyone also recommend me a good book for javascript?
Try this
var originalArray = [{date:"2012-01-01", username: "first"}, {date:"2012-01-02", username: "second"}];
// First step: Get a dateArray with only the dates
var dateArray = [];
for (var i in originalArray) {
dateArray.push(originalArray[i].date);
}
// Or if you prefer to cut a few lines
// dateArray = originalArray.map(function(x) { return x.date; } );
// Second step: Get it as a comma separated string
var datesString = dateArray.join(",");
console.log(dateArray); // ["2012-01-01","2012-01-02"]
console.log(datesString); // 2012-01-01,2012-01-02
One of the more popular books is "Javascript The Good Parts" by Douglas Crockford http://www.amazon.com/JavaScript-Good-Parts-Douglas-Crockford/dp/0596517742
here is the code :
var firstArray = new Array(new Date(), "hello", "something", new Date());
var combined = new Array();
for(i in firstArray) {
if(firstArray[i] instanceof Date) {
combined[combined.length] = firstArray[i];
}
}
var theString = combined.join(",");
alert(combined.length);
alert(theString);
I personally am partial to Javascript the Good parts, but there is a whole community wiki on books for programming. As for your question if you want to use a string, you need to use a string not an array for the combined variable.
array.push({date:created_at,username:user});
var combined = array.map(function(a) { return a.date; }).join(", ");
There are certainly better ways of doing it, but this is just a quick example of something which would work. By concatenating with a string, it implicitly casts the array[i].date into a string if it wasn't already.
Edit: Fixed my code to not be so awful.
