Create comma separated strings from multidimensional array

Question

I have a multidimensional array that looks like this:

[
    Object {href="http://www.somepath.com/car4.png", title="Wheel"},
    Object {href="http://www.somepath.com/car.png", title="Top"},
    Object {href="http://www.somepath.com/car1.png", title="Side"},
    Object {href="http://www.somepath.com/car5.png", title="Saddle"},
    Object {href="http://www.somepath.com/car6.png", title="Front"}
]

I'd like to loop over this object and retrieve two comma seperated strings, one for all hrefs and one for all titles. So what I'm after is:

hrefs = "'http://www.somepath.com/car4.png', 'http://www.somepath.com/car.png', 'http://www.somepath.com/car1.png', 'http://www.somepath.com/car5.png', 'http://www.somepath.com/car6.png'";
titles = "'Wheel', 'Top', 'Side', 'Saddle', 'Front'";

Although it seems pretty easy I lack the knowledge and cant seem to find the specific answer.

Andy · Accepted Answer · 2022-08-30 22:04:30Z

5

A simple function that uses map to get the values into an array, and then join them up.

const arr=[{href:"http://www.somepath.com/car4.png",title:"Wheel"},{href:"http://www.somepath.com/car.png",title:"Top"},{href:"http://www.somepath.com/car1.png",title:"Side"},{href:"http://www.somepath.com/car5.png",title:"Saddle"},{href:"http://www.somepath.com/car6.png",title:"Front"}];

function createString(arr, key) {
  return arr
    .map(obj => `'${obj[key]}'`)
    .join(', ');
}

console.log(JSON.stringify(createString(arr, 'href')));
console.log(JSON.stringify(createString(arr, 'title')));

Additional documentation

Template/string literals

edited Aug 30, 2022 at 22:04

answered Oct 22, 2014 at 12:16

Andy

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3 Comments

Alnitak Over a year ago

@Andy agreed - this is clearly just a "formatted" representation of the object, not actual JS.

M. Page Over a year ago

@Andy ok: I was confused by the csv and multi-dimensional array tags, which are in this case misleading

Solide Over a year ago

I have choosen this as the correct answer as it gives me exactly what I wanted in a clean way.

friedi · Accepted Answer · 2014-10-22 12:15:11Z

0

You could do this:

var hrefs = [],
    titles = [];

data.forEach(function(obj) {
    hrefs.push("'" + obj.href + "'");
    titles.push("'" + obj.title + "'");
});

hrefs = hrefs.join(', ');
titles = titles.join(', ');

answered Oct 22, 2014 at 12:15

friedi

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6 Comments

VLAZ Over a year ago

Just a quick note - forEach is supported in IE9 and above, in case anybody needs to support previous versions.

Andy Over a year ago

Here's the polyfill.

RobG Over a year ago

@Vld—though a for loop is simple, often faster and can be less to type.

Alnitak Over a year ago

It really is about time we stopped having to mention polyfills. ES5 has been out 5 years now - enough is enough!

Andy Over a year ago

When people don't have to support IE8 and lower, perhaps.

|

Rakesh Juyal · Accepted Answer · 2014-10-22 12:27:37Z

0

var data = [
    {href:"http://www.somepath.com/car4.png", title:"Wheel"},
    {href:"http://www.somepath.com/car.png", title:"Top"},
    {href:"http://www.somepath.com/car1.png", title:"Side"},
    {href:"http://www.somepath.com/car5.png", title:"Saddle"},
    {href:"http://www.somepath.com/car6.png", title:"Front"}
],
href = [],
title = [],
dataL = data.length;

for ( i = 0; i < dataL; i++ ){
   href.push ( data[i]['href'] );
   title.push ( data[i]['title'] );
}

href = href.join(",");
title = title.join(",");

answered Oct 22, 2014 at 12:27

Rakesh Juyal

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Comments

Alnitak · Accepted Answer · 2014-10-22 12:41:47Z

0

The canonical function to make an array based on the contents of another array is map. You can then combine that with join to make the required string:

var hrefs = data.map(function(d) { return "'" + d.href + "'" }).join(', ');
var titles = data.map(function(d) { return "'" d.title + "'" }).join(', ');

Note that this would fail to produce valid CSV if there were any single quote signs inside the fields. A solution would be to supply a more rigorous quoting function. Following the usual convention that a quote inside a string should be doubled-up:

function enquote(v) {
    return "'" + v.replace(/'/g, "''") + "'";
}

with usage:

var titles = data.map(function(d) { return enquote(d.title) }).join(', ');

edited Oct 22, 2014 at 12:41

answered Oct 22, 2014 at 12:28

Alnitak

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3 Comments

Rakesh Juyal Over a year ago

This answer looks fine. Why downvote? care to share the reason please.

Andy Over a year ago

I assume it's because the OP doesn't want an array. The OP wants a string of quoted items.

Alnitak Over a year ago

@Andy good point - didn't notice that (was distracted by a colleague). Updated!

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