Simple Pin Validation

Task: ATM machines allow 4 or 6 digit PIN codes and PIN codes cannot contain anything but exactly 4 digits or exactly 6 digits. If the function is passed a valid PIN string, return

Solution 1:

functionvalidatePIN (pin) {
  returntypeof pin === 'string' && // verify that the pin is a stringNumber.isInteger(+pin) && // make sure that the string is an integer when converted into a number
    [4, 6].includes(pin.length) // only accepts 4 and 6 character pins
}

Solution 2:

functionvalidatePIN(pin) {
var isNumber = /^\d+$/.test(pin) && (pin.length == 4 || pin.length == 6)
return isNumber
}

validatePIN('0193')

//returns true

Solution 3:

You can use Array.prototype.every(), Array.prototype.some(), String.prototype.match()

<inputtype="text" /><button>validate pin</button><script>varvalidatePIN = (args) => {[...args] = args;
 return args.every(v => v.match(/\d/)) &&
    [4, 6].some(n => args.length === n)};

  document.querySelector("button")
  .addEventListener("click", (e) =>alert(validatePIN(e.target.previousElementSibling.value))
  )
</script>

Solution 4:

function validatePIN (pin) {
  //return true or falsereturn /^\d+$/.test(pin) && (pin.length === 4 || pin.length === 6)
}

Solution 5:

function validatePIN (pin) {
    if (pin.length !== 4 && pin.length !== 6) {
    returnfalse;
  }
  for (let i = 0; i < pin.length; i++) {
    if (pin[i] > '9' || pin[i] < '0') {
       returnfalse;
    }

  }
  returntrue;
}