ifelseladder.js

/**
 *  A function with an if-else-if ladder
 *   to determine which case conversion is to be done
 */

function changeCase(caseType, ...words) {

    // We support lower and camelCase

    // e.g changeCase("lower", "IoT")
    // or  changeCase("camel", "MY", "VAR")

    // Sanitize user input to "lower", "camel" etc.
    caseType = caseType.trim().toLowerCase();

    // Get ready to convert
    let result = "";

    // Lower case
    if (caseType == "lower") {

        // Concatenate each element as lower
        for (word of words) {
            result += word
                .toString()
                .trim()
                .toLowerCase();
        }
    } else if (caseType == "camel") {

        // first word is lower
        result = words[0]
            .toString()
            .trim()
            .toLowerCase();

        // Now rest of the words are Proper case
        for (let offset = 1;
            offset < words.length;
            offset++) {

            // First letter upper
            result += words[offset]
                .slice(0, 1)
                .toUpperCase();

            // Rest all lower
            result += words[offset]
                .slice(1)
                .toLowerCase();
        }
    }
    return result;
}