JS array index number into value with string replace

Question

I have a multidimentional array:

(3) [Array(1), Array(1), Array(1)]
0:["('idDocDetail','0','$createdBy')"]
1:["('idDocDetail','2','$createdBy'),('idDocDetail','4','$createdBy')"]
2:["('idDocDetail','0','$createdBy')"]

I need to replace the string value idDocDetail with the index number, like this.

(3) [Array(1), Array(1), Array(1)]
0:["('0','0','$createdBy')"]
1:["('1','2','$createdBy'),('1','4','$createdBy')"]
2:["('2','0','$createdBy')"]

I'm trying to use replace, but I got the replace is not a function error.

array.forEach(function(item, index) {
  return item.toString().replace('idDocDetail', index);
    });

what am I doing wrong? Replace is the right way to do this?

Yury Tarabanko · Accepted Answer · 2017-08-17 14:54:57Z

1

I do recommend you to learn to perform changes in immutable manner. This is where Array.prototype.map plays well

const data = [
  ["('idDocDetail','0','$createdBy')"],
  ["('idDocDetail','2','$createdBy'),('idDocDetail','4','$createdBy')"],
  ["('idDocDetail','0','$createdBy')"]
]

const modified = data.map((item, index) => 
   item.map(str => str.replace(/idDocDetail/g, index ))
)

modified.forEach(x => console.log(JSON.stringify(x)))

answered Aug 17, 2017 at 14:54

Yury Tarabanko

45.1k10 gold badges88 silver badges99 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

absolutkarlos Over a year ago

Thanks man, I use prototype.map to extract info from a table to that array, but I get stuck with the index replace. Thanks again!

Christopher Messer · Accepted Answer · 2017-08-17 15:00:16Z

1

Here, this works for your code structure. It uses map() to produce a new array by just replacing the string of interest with the index.

EDIT: Added a nested map for clarity + regular expression to find all instances of 'idDocDetail' in the string, not just the first one. replace method when given a raw string value only handles the first instance of a string occurring.

const array = [["('idDocDetail','0','$createdBy')"],
["('idDocDetail','2','$createdBy'),('idDocDetail','4','$createdBy')"],
["('idDocDetail','0','$createdBy')"]]

var find = 'idDocDetail';
var re = new RegExp(find, 'g');

let newArray = array.map((val, i) => val.map(string => {
  return string.replace(re, i)
}))

console.log(newArray)

edited Aug 17, 2017 at 15:00

answered Aug 17, 2017 at 14:50

Christopher Messer

2,09011 silver badges13 bronze badges

3 Comments

smarber Over a year ago

You're loosing the embedded arrays

absolutkarlos Over a year ago

the second row still have the string I want to replace with the index

Christopher Messer Over a year ago

Code should be all set now

smarber · Accepted Answer · 2017-08-17 15:26:57Z

1

You can loop over your array and edit it.

let array = [
  ["('idDocDetail','0','$createdBy')"],
  ["('idDocDetail','2','$createdBy'),('idDocDetail','4','$createdBy')"],
  ["('idDocDetail','0','$createdBy')"],
];

array.forEach((e, i) => {
  array[i] = [e[0].replace(/idDocDetail/g, i)];
});

console.log(array);

edited Aug 17, 2017 at 15:26

answered Aug 17, 2017 at 14:51

smarber

5,1447 gold badges41 silver badges86 bronze badges

1 Comment

absolutkarlos Over a year ago

the second row still have the string I want to replace with the index

clabe45 · Accepted Answer · 2017-08-17 14:46:30Z

0

You can not replace an item by calling a method on the item being replaced. Instead you need to call it on the array. You can do it this way:

for (var i=0; i<array.length; i++) {
    array[i][0] = i;
}

answered Aug 17, 2017 at 14:46

clabe45

2,47418 silver badges27 bronze badges

Comments

spanky · Accepted Answer · 2017-08-17 14:48:44Z

0

forEach ignores the return of the callback. You need to assign to the original array at the current index.

var array = [
  ["('idDocDetail','0','$createdBy')"],
  ["('idDocDetail','2','$createdBy'),('idDocDetail','4','$createdBy')"],
  ["('idDocDetail','0','$createdBy')"]
];

array.forEach(function(item, index) {
  array[index] = item.map(s => s.replace('idDocDetail', index));
});

console.log(array);

edited Aug 17, 2017 at 14:48

answered Aug 17, 2017 at 14:46

spanky

2,86010 silver badges9 bronze badges

1 Comment

smarber Over a year ago

the second row still have the string 'idDocDetail'

Collectives™ on Stack Overflow

JS array index number into value with string replace

5 Answers 5

1 Comment

3 Comments

1 Comment

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

1 Comment

3 Comments

1 Comment

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related