discord.js get all members with role

//outputs the IDs of all members with the specified role as an array

// === discord.js v11 ===
message.guild.roles.get('ROLE-ID').members.map(m=>m.user.id);

// === discord.js v12 ===
message.guild.roles.cache.get('ROLE-ID').members.map(m=>m.user.id);

let role = message.mentions.roles.first();
if(!role) role = message.guild.roles.cache.find(r => r.id == args[0]);
if(!role) message.reply('that role does not exist!');
let arr = new Array();
role.members.forEach(user => {
	arr.push(`--> **${user.user.username}**`);
});

message.channel.send(arr.join(' | '));