JavaScript program to remove vowels from a string

A string is a sequence of characters that can include alphabets, numbers, and symbols together or separately. In this article, we are going to learn how we can remove vowels from a given string in JavaScript using different approaches.

The five vowels in the English alphabet are: a, e, i, o, u, and they can be both uppercase or lowercase.

Problem Examples

Example 1

Input: Anshu Ayush
Output: nsh ysh

Explanation

The vowels in the string "Anshu Ayush" are A, u, A, u. After removing them, the remaining string is "nsh ysh".

Example 2

Input: crypt
Output: crypt

Explanation

The string "crypt" contains no vowels, so the output remains the same.

Example 3

Input: Tutorials point
Output: Ttrls pnt

Explanation

The vowels in the string are u, o, i, a, o, i. After removing them, the final string is "Ttrls pnt".

Using Direct Logic Approach

In this approach, we use a simple loop to traverse the string completely and check if each character is a vowel or not. If it is a vowel then we skip the character while constructing the new string.

Steps for Implementation

• First, we take a string as the input.
• Now, initialize an empty string to store the result.
• Loop through each character in the string.
• For each character, check if it is a vowel or not.
• If it is not a vowel, add it to the result string.
• Return the modified string.

Implementation Code

let inputStr = "Anshu Ayush";
let outputStr = "";

// Convert string to lowercase for comparison
for (let i = 0; i < inputStr.length; i++) {
    if (!["a", "e", "i", "o", "u"].includes(inputStr[i].toLowerCase())) {
        outputStr += inputStr[i];
    }
}

// Output
console.log("The string after removing vowels is:", outputStr);

The string after removing vowels is: nsh ysh

Time Complexity: O(n)
Space Complexity: O(n)

Using Function Approach

In this approach, we use a function to remove the vowels from a string. This allows us to reuse the logic whenever needed again.

Implementation Code

// Function to remove vowels
function removeVowelsFromString(str) {
    let resultStr = "";
    for (let i = 0; i < str.length; i++) {
        if (!["a", "e", "i", "o", "u"].includes(str[i].toLowerCase())) {
            resultStr += str[i];
        }
    }
    return resultStr;
}

let inputString = "Tutorials point";
let modifiedOutput = removeVowelsFromString(inputString);

console.log("Original string:", inputString);
console.log("After removing vowels:", modifiedOutput);

Original string: Tutorials point
After removing vowels: Ttrls pnt

Using Regular Expression

Regular expressions provide a more concise way to remove vowels using the replace() method with a pattern.

function removeVowelsWithRegex(str) {
    return str.replace(/[aeiouAEIOU]/g, "");
}

let testString = "JavaScript Programming";
let result = removeVowelsWithRegex(testString);

console.log("Original string:", testString);
console.log("After removing vowels:", result);

Original string: JavaScript Programming
After removing vowels: JvScrpt Prgrmmng

Using Filter Method

We can also use the filter() method with array operations to remove vowels.

function removeVowelsWithFilter(str) {
    const vowels = ['a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'];
    return str.split('').filter(char => !vowels.includes(char)).join('');
}

let sampleText = "Hello World";
let filteredText = removeVowelsWithFilter(sampleText);

console.log("Original string:", sampleText);
console.log("After removing vowels:", filteredText);

Original string: Hello World
After removing vowels: Hll Wrld

Performance Comparison

Conclusion

All methods effectively remove vowels from strings. The function approach offers the best reusability, while regular expressions provide the most concise code. Choose based on your specific requirements and coding style preferences.