param str returns public export function isStringEmpty ( str ? ) { return ! str || str . length === 0 ; } example param str returns public export function toKebabCase ( str ) { return str . replace ( /([a-z])([A-Z])/g , '$1-$2' ) . replace ( /\s+|_/g , '-' ) . toLowerCase ( ) ; } example param str returns public export function capitalize ( str ) { return str . charAt ( 0 ) . toUpperCase ( ) + str . slice ( 1 ) ; }