random strings for session tokens etc

rndStr.js

// this one is shorter
rndStr1 = (i=4, f=()=>Math.random().toString(36).slice(2), s='') =>
  { for (;i;--i) s+=f(); return s }
 
// this one is faster
rndStr2 = (n=42,
  l='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz--', s='') =>
    { for (;n;--n) s+=l[Math.random()*62|0]; return s }
    
// this one is with dashes
rndStr3 =()=> rndStr2(36).match(/\w{6}/g).join`-`