regexp logic and or

This question was asked and answered here:

Regular Expressions: Is there an AND operator?

There isn't a direct "and" operator, but you can continue expression testing and ensure the second expression is also a match.

you don't need & operator actually | operator does the job

let string = 'world and earth are awesome';
let regex = /world|earth/ig;

let result = string.replace(regex, '...');

console.log(string);
console.log(result);

If it contains earth AND world, it contains one after the other, so:

earth.*world|world.*earth

an shorter alternative (using extended regex syntax) would be:

/(?=.*earth)(?=.*world).*/

But it is not at all like an and operator. You can only do or because if only one of the words is included, there is no ordering involved. If you want to have them both, you need to indicate the order.

do two tests, if the first fails the second doesn't execute in javascript. e.g.

var hasBoth = /earth/i.test(aString) && /world/i.test(aString);