Avoid string "null" using split method of javascript

Question

I am trying to parse a string with a following format

"value1=name1:value2=test1,value1=name2:value2=null,value1=null:value2=test3"

I would want this to be parsed as

[{ value1: "name1", value2: "test1"}, { value1: "name2", value2: "NA"},{ value1: "NA", value2: "test3"}]

If in case any value post splititng is null , just make is "NA". Since I am using split the null value is being coerced to string. Hence setting "NA" using nullish coalescing(??) is not working and hence it still returns null and not NA. It would also be helpful , If any body can suggest a simpler way to achieve this

Code that I have tried.

let input = "value1=name1:value2=test1,value1=name2:value2=null,value1=null:value2=test3";
let items = input.split(",");
let pairs = items.map((item) => {
 let splitItems = item.split(":");
 let value1 = splitItems[0].split("=")?? "NA";;
 let value2 = splitItems[1].split("=") ?? "NA";
 return { value1, value2 };
});

• Mr. Polywhirl: You can filter out matches containing null values.

Answer 1

You could use the ternary operator

const str =
 "value1=name1:value2=test1,value1=name2:value2=test2,value1=null:value2=test3"
const res = str.split(",").map((el) =>
 el.split(":").reduce((acc, pair) => {
 const [key, value = "NA"] = pair.split("=")
 return {
 ...acc,
 [key]: value === "null" ? "NA" : value,
 }
 }, {})
)
console.log(res)

• user13349816: In case I want it to be parsed as { "SomeVal": "name1", "SomeVal2": "test1"}. rather than taking keys from input, I want a different one in the result?
• hgb123: @li97 then you could change the property as you want, like { [buildKey(key)]: ... } and custom your expected key with the key taken from input

Answer 2

You may try using this:

(string || '').split("=") || "NA"; 

• Gorynych: Step 1. We replace null with empty string step2. We chose splitted strinh or na

Answer 3

What about using Object.fromentries since your split shows two values in the format [],[].

let input = "value1=name1:value2=test1,value1=name2:value2=test2,value1=null:value2=test3";
let items = input.replace(/null/g, 'NA').split(",");
let pairs = items.map((item) => {
 let splitItems = item.split(":");
 let value5 = splitItems[0].split("=");
 let value6 = splitItems[1].split("=");
 return Object.fromEntries([value5,value6])
});
console.log(pairs)

Answer 4

maybe that is not a simpler but easy and saver way to parse your string, and it is versatile enough to provide key value pairs as many where provided

const input = "value1=name1:value2=test1:value3=name3:value4=test4,value1=name2:value2=test2,value1=null:value2=test3";
const mappedKey = {
 value3: 'someNewKey1',
 value4: 'someNewKey2',
};
const parseData = (input) => {
 // replace directly all null values before splitting
 const stream = input.replace(/null/g, 'NA');
 // now split by comma and equal sign
 const parsedStream = stream.split(",").map((fragment) => {
 // build a key value object, to be able to collect n value pairs
 const obj = {};
 // split groups by -> :
 const values = fragment.split(':').map((split) => {
 // split key value pairs by -> =
 return split.split('=');
 });
 // collect the key value pais into obj
 values.forEach((data) => {
 const [key, value] = data;
 obj[mappedKey[key] || key] = value;
 });
 // return the final result
 return obj;
 });
 
 return parsedStream;
}
window.onload = () => {
 document.querySelector('.input').innerHTML = input;
 document.querySelector('.result').innerHTML = JSON.stringify(parseData(input), null, 2);
}

<h3>Input:</h3>
<pre class="input"></pre>
<hr />
<h3>Parsed result:</h3>
<pre class="result"></pre>