Vowel/Consonant Check - JavaScript Program

// Method 1: Using if-else function checkVowelConsonant(char) { // Convert to lowercase for case-insensitive check char = char.toLowerCase(); if (char === 'a' || char === 'e' || char === 'i' || char === 'o' || char === 'u') { return "Vowel"; } else if (char >= 'a' && char <= 'z') { return "Consonant"; } else { return "Not a letter"; } } console.log("a:", checkVowelConsonant('a')); console.log("B:", checkVowelConsonant('B')); console.log("z:", checkVowelConsonant('z')); console.log("5:", checkVowelConsonant('5')); // Method 2: Using array includes() function checkVowelConsonant2(char) { char = char.toLowerCase(); const vowels = ['a', 'e', 'i', 'o', 'u']; if (vowels.includes(char)) { return "Vowel"; } else if (char >= 'a' && char <= 'z') { return "Consonant"; } else { return "Not a letter"; } } console.log("\nUsing includes():"); console.log("e:", checkVowelConsonant2('e')); console.log("k:", checkVowelConsonant2('k')); // Method 3: Using switch statement function checkVowelConsonant3(char) { char = char.toLowerCase(); switch(char) { case 'a': case 'e': case 'i': case 'o': case 'u': return "Vowel"; default: if (char >= 'a' && char <= 'z') { return "Consonant"; } else { return "Not a letter"; } } } console.log("\nUsing switch:"); console.log("i:", checkVowelConsonant3('i')); console.log("m:", checkVowelConsonant3('m'));

This program demonstrates different ways to check if a character is a vowel or consonant.

Vowels and Consonants

Vowels: a, e, i, o, u (and sometimes y)
Consonants: All other letters

Method 1: If-Else with OR

Using logical OR (||) operator:

javascript
if (char === 'a' || char === 'e' || char === 'i' || char === 'o' || char === 'u') {
    return "Vowel";
}

String Methods

toLowerCase(): Converts to lowercase
toUpperCase(): Converts to uppercase
charAt(): Gets character at index

Method 2: Array includes()

Using array method (ES6):

javascript
const vowels = ['a', 'e', 'i', 'o', 'u'];
if (vowels.includes(char)) {
    return "Vowel";
}

Pros:

Cleaner code
Easy to modify vowels
More readable

Method 3: Switch Statement

Using switch for multiple cases:

javascript
switch(char) {
    case 'a':
    case 'e':
    case 'i':
    case 'o':
    case 'u':
        return "Vowel";
    default:
        return "Consonant";
}

Switch Statement

Checks value against multiple cases
break exits switch (not needed with return)
default handles unmatched cases

Character Validation

Check if character is a letter:

javascript
if (char >= 'a' && char <= 'z') {
    // It's a letter
}

When to Use:

If-else: Simple conditions
includes(): Modern, clean
Switch: Multiple exact matches

Output

Vowels and Consonants

Vowels: a, e, i, o, u (and sometimes y)

Consonants: All other letters