Uncover the valuable information within a string using regex in JavaScript

Question

Uncover the valuable information within a string using regex in JavaScript

I am looking for a solution to extract key values from a string that looks like this: 

My goal is to create a standard function that can extract any value needed. The function call would be something like: var name=ExtractValue(text,"Name");

Here is my proposed approach:

var text="<!-- Name:Peter Smith --><!-- Age:23 -->"; // Data to be scanned

var name=ExtractValue(text,"Name"); // Get the "Name" key value
var age=ExtractValue(text,"Age");   // Get the "Age" key value
document.getElementById("result").innerHTML = "Extracted name: ("+name+"), age: ("+age+")";

// Function for extracting key values
function ExtractValue(data,key){
    // It should work similarly to /Name:(.*)\s--/
    var rx = "/"+key+"(.*)\s--/";
    var values = rx.exec(data);
    if(values.length>0){
        return values[1];
    } else{
        return "";
    }
}

Any suggestions on how I can achieve this? Thanks for your help!

javascript regex

Answer 1

Answer №1

Here is a way to achieve it:

var text="<!-- Name:Peter Smith --><!-- Age:23 -->"; // Information to be extracted

var name=ExtractValue(text,"Name"); // Retrieving the value for "Name"
var age=ExtractValue(text,"Age");   // Obtaining the value for "Age"
console.log("Extracted name: ("+name+"), age: ("+age+")");

function ExtractValue(data,key){
    var rx = new RegExp(key + ":(.*?)\\s+--");
    var values = rx.exec(data); // Alternatively: data.match(rx);
    return values && values[1];
}

Remember to use double backslashes in a string literal, like "\\s" instead of "\s", to ensure correct interpretation. Also, make sure to include colons in your regular expressions and verify property names such as length for accuracy to avoid logic errors.

Note that exec and match will return null if there is no match, so don't assume the existence of a length property.

Answer 2

Here is a way to achieve it:

var text="<!-- Name:Peter Smith --><!-- Age:23 -->"; // Information to be extracted

var name=ExtractValue(text,"Name"); // Retrieving the value for "Name"
var age=ExtractValue(text,"Age");   // Obtaining the value for "Age"
console.log("Extracted name: ("+name+"), age: ("+age+")");

function ExtractValue(data,key){
    var rx = new RegExp(key + ":(.*?)\\s+--");
    var values = rx.exec(data); // Alternatively: data.match(rx);
    return values && values[1];
}

Remember to use double backslashes in a string literal, like "\\s" instead of "\s", to ensure correct interpretation. Also, make sure to include colons in your regular expressions and verify property names such as length for accuracy to avoid logic errors.

Note that exec and match will return null if there is no match, so don't assume the existence of a length property.

Answer 3

Answer №2

This method retrieves an object containing all the identified key/value pairs. Afterwards, users can easily locate specific keys within the object.

var text = "<!-- Name:John Doe --><!-- Age:30 --><!-- Occupation:Developer -->";

var data = ExtractData(text);
console.log(data);
console.log("Retrieved name: (" + data["Name"] + "), age: (" + data["Age"] + ")");

function ExtractData(data) {
  var matches = data.match(/([A-Za-z\s]+:[^\-\-\>]+)/g);
  var extractedData = {};

  if (Array.isArray(matches)) {
    matches.forEach(function(match) {
      var pair = match.split(":");
      if (pair.length === 2) {
        extractedData[pair[0].trim()] = pair[1].trim();
      }
    });
  }

  return extractedData;
}

Answer 4

This method retrieves an object containing all the identified key/value pairs. Afterwards, users can easily locate specific keys within the object.

var text = "<!-- Name:John Doe --><!-- Age:30 --><!-- Occupation:Developer -->";

var data = ExtractData(text);
console.log(data);
console.log("Retrieved name: (" + data["Name"] + "), age: (" + data["Age"] + ")");

function ExtractData(data) {
  var matches = data.match(/([A-Za-z\s]+:[^\-\-\>]+)/g);
  var extractedData = {};

  if (Array.isArray(matches)) {
    matches.forEach(function(match) {
      var pair = match.split(":");
      if (pair.length === 2) {
        extractedData[pair[0].trim()] = pair[1].trim();
      }
    });
  }

  return extractedData;
}

Answer 5

Answer №3

If you're looking to avoid using regex, consider utilizing the string split function instead.

var text = "<!-- Name:Peter Smith --><!-- Age:23 -->"; // Data that needs to be parsed
var obj = ExtractToObj(text);
document.getElementById("result").innerHTML = "Extracted name: (" + obj["Name"] + "), age: (" + obj["Age"] + ")";

function ExtractToObj(data) {
  var obj = {};
  var kvps = data.split("-->").filter(function(n) {
    return n !== ""; // Remove empty elements
  });
  for (var i = 0; i < kvps.length; i++) {
    var kvp = kvps[i].split(":");
    var key = kvp[0].replace("<!--", "").trim();
    var value = kvp[1].trim();
    obj[key] = value;
  }
  return obj;
}

Here is a demo link on JSFiddle

Answer 6

If you're looking to avoid using regex, consider utilizing the string split function instead.

var text = "<!-- Name:Peter Smith --><!-- Age:23 -->"; // Data that needs to be parsed
var obj = ExtractToObj(text);
document.getElementById("result").innerHTML = "Extracted name: (" + obj["Name"] + "), age: (" + obj["Age"] + ")";

function ExtractToObj(data) {
  var obj = {};
  var kvps = data.split("-->").filter(function(n) {
    return n !== ""; // Remove empty elements
  });
  for (var i = 0; i < kvps.length; i++) {
    var kvp = kvps[i].split(":");
    var key = kvp[0].replace("<!--", "").trim();
    var value = kvp[1].trim();
    obj[key] = value;
  }
  return obj;
}

Here is a demo link on JSFiddle

Answer 7

Answer №4

If I were to approach this task, I might consider the following:

const data = `<div><!-- Name   : Peter Smith --><!-- Age:23 -->some test data that is not found</div>`

const getData = data => {
  const obj = {}, regex = /<!--\s*(.*?)\s*:\s*(.*?)\s*-->/g
  let temp
  while (temp = regex.exec(data)){
    obj[temp[1]] = temp[2]
  }
  return obj
}

const personInfo = getData(data)
console.log(`Extracted name: (${personInfo.Name}), age: (${personInfo.Age})`)

Alternatively, if you only need to extract a single property:

const data = `<div><!-- Name   : Peter Smith --><!-- Age:23 -->some test data that is not found</div>`

const getData = (data, key) => (data.match(new RegExp(`<!--\\s*${key}\\s*:\\s*(.*?)\\s*-->`)) || [, null])[1]

console.log(`${getData(data, 'Name')}`)

Answer 8

If I were to approach this task, I might consider the following:

const data = `<div><!-- Name   : Peter Smith --><!-- Age:23 -->some test data that is not found</div>`

const getData = data => {
  const obj = {}, regex = /<!--\s*(.*?)\s*:\s*(.*?)\s*-->/g
  let temp
  while (temp = regex.exec(data)){
    obj[temp[1]] = temp[2]
  }
  return obj
}

const personInfo = getData(data)
console.log(`Extracted name: (${personInfo.Name}), age: (${personInfo.Age})`)

Alternatively, if you only need to extract a single property:

const data = `<div><!-- Name   : Peter Smith --><!-- Age:23 -->some test data that is not found</div>`

const getData = (data, key) => (data.match(new RegExp(`<!--\\s*${key}\\s*:\\s*(.*?)\\s*-->`)) || [, null])[1]

console.log(`${getData(data, 'Name')}`)

Uncover the valuable information within a string using regex in JavaScript

Answer №1

Answer №2

Answer №3

Answer №4

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