const kebabCase = string => string
.replace(/([a-z])([A-Z])/g, "$1-$2")
.replace(/[s_]+/g, '-')
.toLowerCase();
console.log(kebabCase('Geeks For Geeks'));
console.log(kebabCase('GeeksForGeeks'));
console.log(kebabCase('Geeks_For_Geeks'));