How to build a simple string from a multidimensional array?

Question

Basically, I have a multidimensional array that I need to build into a simple string.

Quite an easy question, although it has been eating away at me for quite some time now since I can't seem to nail it.

Here is an example of how my array could look with just 3 questions within it:

[["question1","answer1","answer2","answer3","answer4"],["question2","answer1","answer2","answer3","answer4"],["question3","answer1","answer2","answer3","answer4"]]

For example, D.rows[0][0] would be "question1" and D.rows[2][3] would be "answer3", just to clarify.

Here is how it must be saved into a string as:

question1,answer1,answer2,answer3,answer4 
question2,answer1,answer2,answer3,answer4 
question3,answer1,answer2,answer3,answer4

Each element must have a comma between them, and each question must be separated by a line-break.

This is what I currently have that is not working:

var fullString;
for (i = 0; i < csvArray.length; ++i) 
{
    second = secondArray[i];
    for (j = 0; j < second.length; ++j) 
    {
        fullString += entry[j] + "'";
    }
    fullString += "\n";
}

Thanks in advance!

Jaak Kütt · Accepted Answer · 2013-08-24 07:12:08Z

1

try this

var s,a=[["question1","answer1","answer2","answer3","answer4"],"question2","answer1","answer2","answer3","answer4"],["question3","answer1","answer2","answer3","answer4"]];
for(i=0; i < a.length; i++){
    s=(s)?s+"\n\r"+a[i].join():a[i].join();
}

jsfiddle example

In your own example: since you are going straight to adding to fullString, it should have an empty string for value, otherwise you will end up with undefined in the beginning.

var fullString="";

this part second = secondArray[i]; should have been

var second = csvArray[i];

and in a same way this fullString += entry[j] + "'"; should have been

fullString += second[j] + ",";

edited Aug 24, 2013 at 7:12

answered Aug 24, 2013 at 6:09

Jaak Kütt

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2 Comments

magyar1984 Over a year ago

@fizzix - in for in loop order of iteration is not specified in ecma script spec - results may vary in different browsers, also if you add to array prototype in ES3, you will get that too - use for(i=0; i < arr.length; i+=1)

Jaak Kütt Over a year ago

thanks @magyar1984 for the notice, been on ES5 for a while now and tend to forget some of the differences ^^. But personally I would even recommend going with the answer given by spy-js

spy-js · Accepted Answer · 2013-08-24 06:18:22Z

1

one liner:

var result = [["question1","answer1","answer2","answer3","answer4"],["question2","answer1","answer2","answer3","answer4"],["question3","answer1","answer2","answer3","answer4"]].join('\r\n');

edited Aug 24, 2013 at 6:18

answered Aug 24, 2013 at 6:13

spy-js

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Comments

naed11 · Accepted Answer · 2013-08-24 06:02:12Z

0

something like this:

var questionAnswerSet= { "question1" : [
{ "answer1" : "value", "answer2" : "value", "answer3" : value} ],
"question2" : [
{ "answer1" : "value", "answer2" : "value", "answer3" : value} ], }

and access like this:

questionAnswerSet[0].answer2 // question one answer 2

questionAnswerSet[1].answer2 // question two answer 2

answered Aug 24, 2013 at 6:02

naed11

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2 Comments

Fizzix Over a year ago

Sorry, but that makes no sense at all? I believe that I need a double for loop to go over every element within my array.

Fizzix Over a year ago

My array can have any amount of entries? And the elements will always be different...

naed11 · Accepted Answer · 2013-08-24 06:10:03Z

0

for (var i=0; i<yourArray.length; i++) { // iterate on the array
   var obj = yourArray[i];
   for (var key in obj) { // iterate on object properties
      var value = obj[key];
      console.log(value);
   }
}

answered Aug 24, 2013 at 6:10

naed11

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Comments

Faisal Sayed · Accepted Answer · 2013-08-24 06:14:38Z

0

If you have an array as this...

var arr = [["question1","answer1","answer2","answer3","answer4"],["question2","answer1","answer2","answer3","answer4"],["question3","answer1","answer2","answer3","answer4"]];

then...

var strArr  =  arr.join(',');
var strLine =  arr.join('\n'); // string with line breaks.

will do that for you.

if you want different strings for each question-answer block, then...

var strJoinArr = [], strJoinLines = '';
for(var i = 0; i < arr.length; i++){
    strJoinArr.push(arr[i].join(','));
    strJoinLines += arr[i].join(',')+ '\n'; // string with line break
}

then to access each section you can use indexes,

For example, strJoinArr[2] will return 'question3,answer1,answer2,answer3,answer4'

1 Comment

Fizzix Over a year ago

How does that add the line breaks?

Rastko · Accepted Answer · 2013-08-24 06:17:56Z

0

This might be your solution if you plan ot change separators or number of answers.

var array = [["question1","answer1","answer2","answer3","answer4"],["question2","answer1","answer2","answer3","answer4"],["question3","answer1","answer2","answer3","answer4"]],
string = "";

for (var i = 0; i <= array.length - 1; i++) {
     string +=array[i].join(', ');
     string += "\n";
}

Also, in the less readable but also effective way, for any object of this structure

string = array.join('\r\n');

answered Aug 24, 2013 at 6:17

Rastko

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