Javascript Compare Strings Without Being Case Sensitive Duplicate

When working with strings in JavaScript, you might often come across the need to compare two strings without being case-sensitive and also looking out for duplicates. This can be a common scenario, especially when handling user inputs or checking for unique values in a dataset. In this article, we will explore how you can achieve this efficiently in your JavaScript code.

One of the most straightforward ways to compare strings in a case-insensitive manner while also checking for duplicates is by converting both strings to lowercase or uppercase before performing the comparison. This approach ensures that the case difference between the characters is ignored during the comparison process.

Here's a simple example to demonstrate this concept:

Javascript

function compareStringsIgnoreCase(str1, str2) {
  return str1.toLowerCase() === str2.toLowerCase();
}

function checkForDuplicateStrings(inputArray) {
  const uniqueValues = new Set();
  const duplicateStrings = [];

  inputArray.forEach((str) =&gt; {
    const lowercaseStr = str.toLowerCase();

    if (uniqueValues.has(lowercaseStr)) {
      duplicateStrings.push(str);
    } else {
      uniqueValues.add(lowercaseStr);
    }
  });

  return duplicateStrings;
}

const string1 = "Hello";
const string2 = "hello";
const string3 = "world";
console.log(compareStringsIgnoreCase(string1, string2)); // true

const inputArray = ["Apple", "orange", "Banana", "apple", "banana"];
console.log(checkForDuplicateStrings(inputArray)); // ["apple", "banana"]

In the `compareStringsIgnoreCase` function, both input strings are converted to lowercase using the `toLowerCase()` method before the comparison is made. This ensures that the comparison is case-insensitive, and the function returns `true` if the strings are equal disregarding the case.

The `checkForDuplicateStrings` function demonstrates how you can identify duplicate strings in an array by converting each string to lowercase and utilizing a `Set` data structure to keep track of unique values. If a lowercase version of a string is already present in the set, it is considered a duplicate and added to the `duplicateStrings` array.

By implementing these two functions in your JavaScript code, you can easily compare strings without considering case sensitivity and detect duplicates efficiently. This approach can be particularly useful in scenarios where case differences should not affect the comparison results and when managing datasets with string values that need to be unique.

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