Convert a string in JavaScript to Pascal Case (removing non alphabetic characters).

string-to-pascal-case.ts

declare global {
    interface String {
        toPascalCase(): string;
    }
}

/**
 * Convert a string to Pascal Case (removing non alphabetic characters).
 *
 * @example
 * 'hello_world'.toPascalCase() // Will return `HelloWorld`.
 * 'fOO BAR'.toPascalCase()     // Will return `FooBar`.
 *
 * @returns {string}
 *   The Pascal Cased string.
 */
String.prototype.toPascalCase = function(): string {
    const words = this.match(/[a-z]+/gi);
    if (!words) return "";
    return words
        .map(function(word) {
            return word.charAt(0).toUpperCase() + word.substr(1).toLowerCase();
        })
        .join("");
};