javascript generate random string

function gen_string(length){
	let result='';
	const characters='ABCDEFGHJKMNPQRSTUVWXYZ23456789';
	const charactersLength=characters.length;
	let counter=0;
	while(counter<length){
		result+=characters.charAt(Math.floor(Math.random()*charactersLength));
		counter+=1;
	}
	return result;
}

$(document).ready(function(){
	$('.gen i').on('click',function(){
		var str=gen_string(5);
		$(this).closest('.gen').find('input').val(str);
	});
});