find capital word in string javascript

1//capitalize only the first letter of the string. 
2function capitalizeFirstLetter(string) {
3    return string.charAt(0).toUpperCase() + string.slice(1);
4}
5//capitalize all words of a string. 
6function capitalizeWords(string) {
7    return string.replace(/(?:^|\s)\S/g, function(a) { return a.toUpperCase(); });
8};

1"thisIsATrickyOne".split(/(?=[A-Z])/);
2

1function toTitleCase(str) {
2    return str.replace(/\w\S*/g, function(txt){
3        return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();
4    });
5}

1const capitalizeFirstLetter(string) => 
2	string.charAt(0).toUpperCase() + string.slice(1).toLowerCase()

1const str = "HERE'S AN UPPERCASE PART of the string";
2const upperCaseWords = str.match(/(\b[A-Z][A-Z]+|\b[A-Z]\b)/g);
3
4console.log(upperCaseWords);