Javascript Array dont print empty value

Question

I have this code below with 3 arrays and sometime the green array will be completely empty how do i make it so that when i combine all my arrays and loop through my foreach it doesn't print undefined value? Any help would be greatly appreciated.

var blue = job['blue-color'];
var red = job['red-color'];
var green = job['green-color']; 
var colors = blue .concat(red,green);


var colorbooks = '<div">';
$.each(colors, function (index) {
  colorbooks += '<div">' + colors[index] + '</div>';
});
colorbooks+= '</div>';

can you show job ?

Damian Peralta
– Damian Peralta

2018-06-27 07:31:52 +00:00
Commented Jun 27, 2018 at 7:31 — Damian Peralta
– Damian Peralta, Commented Jun 27, 2018 at 7:31

Zenoo · Accepted Answer · 2018-06-27 07:38:06Z

2

You could just check if your value is truthy before printing it :

var blue = job['blue-color'] || [];
var red = job['red-color'] || [];
var green = job['green-color'] || [];
var colors = blue.concat(red, green);


var colorbooks = '<div">';
$.each(colors, function(index) {
                            //If it's undefined, it will print an empty String instead
  colorbooks += '<div">' + (colors[index] || '') + '</div>';
});
colorbooks += '</div>';

As @Margon advised in the comments, if job['XXX-color'] is undefined, you can also assign an empty array to your variable instead : var blue = job['blue-color'] || [];

edited Jun 27, 2018 at 7:38

answered Jun 27, 2018 at 7:31

Zenoo

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3 Comments

Margon Over a year ago

May I suggest to also check also "job['X-color']" is different from undefined? Like you did in your (colors[index] || '') So it become (job['green-color'] || []) and so on..

Best Jeanist Over a year ago

@Zenoo is there no way to make it print nothing instead?

Zenoo Over a year ago

@Bobby That's exactly what that does.

Ankit Agarwal · Accepted Answer · 2018-06-27 07:33:14Z

0

You can first use filter() to get the defined values only and then use forEach() to console.log all those values:

var blue = [''];
var red = ['red1'];
var green = ['', 'blue1']
var colors = blue .concat(red,green);
console.log(colors);
colors.filter(item => item).forEach(x => console.log(x));

answered Jun 27, 2018 at 7:33

Ankit Agarwal

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Comments

Aman Deep · Accepted Answer · 2018-06-27 07:38:49Z

0

This might help

<script>

var a = [''];
var b= ['red1'];
var v = ['', 'blue1']
var colors = v .concat(a,b);
$.each(colors,function(index,value){
alert(value);
});

</script>

answered Jun 27, 2018 at 7:38

Aman Deep

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