I am trying to print out this code in a string.

var x = [[1, 2, 3, 4.5, 6], [7, 8.5, 9.5, 10]];`
console.log(x.toString());

This is what shows up.

When I print out the regular string, like so-

console.log(x);

This is what shows up-

Is there any way I can print out a string with the square brackets? I want the result to be something like "[[1, 2, 3, 4.5, 6], [7, 8.5, 9.5, 10]]".

I need to add this value to a eval function, which is why I need to add the entire array (as a string with the brackets) to the function.

Is there any way this can be possible (preferably without additional libraries)?

I am trying to print out this code in a string.

var x = [[1, 2, 3, 4.5, 6], [7, 8.5, 9.5, 10]];`
console.log(x.toString());

This is what shows up.

When I print out the regular string, like so-

console.log(x);

This is what shows up-

Is there any way I can print out a string with the square brackets? I want the result to be something like "[[1, 2, 3, 4.5, 6], [7, 8.5, 9.5, 10]]".

I need to add this value to a eval function, which is why I need to add the entire array (as a string with the brackets) to the function.

Is there any way this can be possible (preferably without additional libraries)?

• javascript
• arrays
• string
• eval
• string-conversion

• 1 Why are you using eval? – Explosion Pills Commented Feb 19, 2016 at 3:02
• @ExplosionPills the eval function doesn't have to do with the question- but I said that anyway to state why exactly I needed to have the array in a string. I am using eval to assign this value to a variable, but instead the first image shown above is being assigned to the variable, which is causing many errors. This is why I am using eval. – Ron Commented Feb 19, 2016 at 3:13
• 1 What do you need eval to assign it to a variable instead of just assigning the array to the variable? I know that eval doesn't have to do with your specific question, but I'm thinking it's a possible XY problem. – Explosion Pills Commented Feb 19, 2016 at 3:23

4 Answers 4

Use JSON.stringify to convert the Array to a JSON Array.

var x = [[1, 2, 3, 4.5, 6], [7, 8.5, 9.5, 10]];
console.log(JSON.stringify(x));
// [[1,2,3,4.5,6],[7,8.5,9.5,10]]

You can use JSON.stringify() to serialize x into a string.

console.log(JSON.stringify(x)) will return what you're looking for.

 console.log(JSON.stringify(x))
 [[1,2,3,4.5,6],[7,8.5,9.5,10]]

You can use Array#map with string concatenation.

'[' + x.map(e => '[' + e + ']') + ']'

var x = [
  [1, 2, 3, 4.5, 6],
  [7, 8.5, 9.5, 10]
];

var string = '[' + x.map(e => '[' + e + ']') + ']';
console.log(string);
document.body.innerHTML = string;

If the elements of the main array are not always array, Array.isArray can be used with ternary operator.

'[' + x.map(e => Array.isArray(e) ? '[' + e + ']' : e) + ']'

var x = [
    [1, 2, 3, 4.5, 6],
    [7, 8.5, 9.5, 10],
    'name',
    10
];

var string = '[' + x.map(e => Array.isArray(e) ? '[' + e + ']' : e) + ']';
console.log(string);
document.body.innerHTML = string;

The best way is to use the json.stringify() method.The JSON.stringify() method converts a JavaScript value to a JSON string, optionally replacing values if a replacer function is specified, or optionally including only the specified properties if a replacer array is specified. MAy the below url help you where you can get plete reference.

https://developer.mozilla/en/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify