How do I convert a string which is in the form of Array of objects to JSON in node.js

Question

This is my string

let data = "[{Date: 2002,Entity Taking Action: Maryland Board ,Action Taken: Reprimand},{Date: 2002,Entity Taking Action: Massachusetts Board,Action Taken: Consent order because of Maryland Board},{Date: 2007,Entity Taking Action: North Carolina Medical Board,Action Taken: Consent order because of Maryland Board action},{Date: 2013,Entity Taking Action: NC Medical Board,Action Taken: Letter of concern for not reporting previous NC consent order on reactivation of NC licence}]"

Answer 1

1. Your best solution may be to ask the provider of that string not to think that what he provides is useful. There is high probability that it was some minor mistake or at least with very few effort on his side he can provide a better structured format (at least directly the yaml or something)

2. If you still have to doityourself you may

   • Try to convert the string as a jsonparsable one

let data = "[{Date: 2002,Entity Taking Action: Maryland Board ,Action Taken: Reprimand},{Date: 2002,Entity Taking Action: Massachusetts Board,Action Taken: Consent order because of Maryland Board},{Date: 2007,Entity Taking Action: North Carolina Medical Board,Action Taken: Consent order because of Maryland Board action},{Date: 2013,Entity Taking Action: NC Medical Board,Action Taken: Letter of concern for not reporting previous NC consent order on reactivation of NC licence}]"
const t = data
  .replace(/([{,]\s*)([^{:]*)(:)/g, '$1"$2"$3') // replace keys
  .replace(/(:\s*)([^},]*)([,}])/g, (all, $1, $2, $3) => { // replace values
    let val = $2
    if (parseInt($2) != $2) {
      val = `"${$2}"`
    }
    return `${$1}${val}${$3}`
  }) // replace values
console.log('t : ', JSON.parse(t))

• Or parse it yourself

let data = "[{Date: 2002,Entity Taking Action: Maryland Board ,Action Taken: Reprimand},{Date: 2002,Entity Taking Action: Massachusetts Board,Action Taken: Consent order because of Maryland Board},{Date: 2007,Entity Taking Action: North Carolina Medical Board,Action Taken: Consent order because of Maryland Board action},{Date: 2013,Entity Taking Action: NC Medical Board,Action Taken: Letter of concern for not reporting previous NC consent order on reactivation of NC licence}]"
const s = data.match(/{([^}]*)}/g).map(objStr => {
  const stripped = objStr.substring(1, objStr.length - 1)
  const o = stripped.split(',')
    .map(keyval => keyval.split(':'))
    .map(([k, v]) => {
      let val = parseInt(v)
      if (val != v) {
        val = v.trim()
      }
      return [k.trim(), val]
    })
  return Object.fromEntries(o)
})
console.log(s)

But recall that those are "tries" only since you don't know what kind of weird input your provider may give you in the future...

Answer 2

You can parse your weird input data with a series of nested regular expressions, using RegExp.exec() and one String.split().

  const data = "[{Date: 2002,Entity Taking Action: Maryland Board ,Action Taken: Reprimand},{Date: 2002,Entity Taking Action: Massachusetts Board,Action Taken: Consent order because of Maryland Board},{Date: 2007,Entity Taking Action: North Carolina Medical Board,Action Taken: Consent order because of Maryland Board action},{Date: 2013,Entity Taking Action: NC Medical Board,Action Taken: Letter of concern for not reporting previous NC consent order on reactivation of NC licence}]"
  const array = []
  console.log ('data', data);
  const regex1 = RegExp(/^\[(.*?)\]$/, 'g')
  while (true) {
    const rr1 = regex1.exec(data)
    if (!rr1) break
    const r1 = rr1[1]
    const regex2 = RegExp(/{(.+?)},?/, 'g')
    while (true) {
      let rr2 = regex2.exec(rr1)
      if (!rr2) break
      const r2 = rr2[1]
      const item = {}
      console.log('item', r2)
      const splits = r2.split(',')
      for (let key in splits) {
          let tagValue = splits[key]
          console.log ('tagValue', tagValue)
          const regex4 = RegExp(/ *(.+): *(.+) */, 'g')
          while (true) {
              const rr4=regex4.exec(tagValue)
              if (!rr4) break
              const tag = rr4[1]
              const val = rr4[2]
              item[tag] = val
              console.log ('field', tag, val)
          }
      }
      array.push(item)
      console.log ('item', item)
    }  
  }
  console.log(JSON.stringify(array))

The outermost RegExp(/^\[(.*?)\]$/, 'g') removes the [] delimiters.

The next one RegExp(/{(.+?)},?/, 'g') splits up your {some thing},{another thing},{yet another} data into some thing, another thing, and yet another, removing the {} curly braces as it does so.

The string.split turns your Tag: value, Tag: value sequence into individual Tag: value items.

And the innermost RegExp(/ *(.+): *(.+) */, 'g') turns those into tag and val items.

You know, it's said that if you solve a problem with a regular expression, you then have two problems. This solution uses three regular expressions, so now you have four problems. The point is that regular-expression parsing is brittle. For example, if one of your Action Taken items says Disbarred, then thrown in federal prison, that extra comma will wreck this parser.

You could write a robust parser for this stuff. But your better bet is to tell the provider of your data you need real JSON.