Answers for "regex match 1 or empty"

regex to check non empty string

/^(?!\s*$).+/

regex empty string

const REGEXP = /^$/;

const validate = (text) => {     
    return REGEXP.test(text);
}

const isEmpty = validate("");
const isNotEmpty = validate("x");

console.log(isEmpty); //true
console.log(isNotEmpty); //false