How to use a Set in JavaScript In Javascript
In this approach we use a Set to efficiently find and store duplicate characters in a given string. It iterates through the string, adding each character to the Set if it’s not already present, and adds it to the ‘duplicates’ array if it’s encountered again.
Syntax:
new Set([it]);
Example: In this example we are using above explained apporach.
const str = "w3wiki";
const cSet = new Set();
const duplicates = [];
for (let i = 0; i < str.length; i++) {
const char = str[i];
if (cSet.has(char)) {
if (!duplicates.includes(char)) {
duplicates.push(char);
}
} else {
cSet.add(char);
}
}
if (duplicates.length > 0) {
console.log(
`The String ${str} has duplicate characters: ${duplicates.join(", ")}`);
} else {
console.log(`The String ${str} has all unique characters`);
};
Output
The String w3wiki has duplicate characters: e, G, k, s
JavaScript Program to Check for Repeated Characters in a String
In this article, we are going to see various methods with which you can detect repeated characters in a string. Checking for repeated characters in a string involves examining the string’s content to identify if any character occurs more than once. This helps detect duplications or repetitions within the text.
Input: Str = “w3wiki”
Output:
e, count = 4
g, count = 2
k, count = 2
s, count = 2
Explanation: e,g,k,and s are characters which are occured in string in more than one times.
There are several methods that can be used to Check for repeated characters in a string JavaScript.
Table of Content
- Using sort() method with for…of loop
- Using a Set in JavaScript
- Without using Extra Data Structure
- Using a Map
- Using Object as a Frequency Counter:
We will explore all the above methods along with their basic implementation with the help of examples.