Utilizing Javascript's every() method to verify if all elements in an array are integers

Question

Utilizing Javascript's every() method to verify if all elements in an array are integers

I am currently working on a function that needs to return true if an array contains all integers, and false if it does not. I am incorporating the every method for this purpose, which is documented on MDN here.

For example, if the input is '1234', the function should return true, whereas if the input is '123a', it should return false.

function validatePIN(pin) {
    let pinArray = pin.split("");
    if (pinArray.length === 4 || pinArray.length === 6) {
        if (pinArray.every(element => !isNaN(element))) {
            return true;
        }
    }
}

I am curious about the mechanism by which the every method passes each element to isInteger for testing. How exactly does this process work?

javascript arrays

Answer 1

Answer №1

After correcting the syntax error and passing Number.isInteger as a function, the code still won't work.

function wrongValidatePIN (pin) {
    var pinArray = pin.split(""); // <-- array of strings
      if (pinArray.length === 4 || pinArray.length === 6) {
        if (pinArray.every(Number.isInteger)) { // <-- isInteger works with numbers
          return true
    }}
    return false
}

console.log(wrongValidatePIN('1234'))

A more suitable solution would be like this

    function validatePIN (pin) {
        var pinArray = pin.split(""); // <-- array of strings
        
        return (pinArray.length === 4 || pinArray.length === 6)
           && pinArray.every(char => !Number.isNaN(Number.parseInt(char, 10)))
    }

    console.log(validatePIN('1234'), validatePIN('123a'))

Alternatively, you could use regular expressions

function validatePin(pin) {
  return /^(\d{4}|\d{6})$/.test(pin)
}

console.log(validatePin('1234'), validatePin('123456'),
 validatePin('12345'), validatePin('123a'))

Answer 2

After correcting the syntax error and passing Number.isInteger as a function, the code still won't work.

function wrongValidatePIN (pin) {
    var pinArray = pin.split(""); // <-- array of strings
      if (pinArray.length === 4 || pinArray.length === 6) {
        if (pinArray.every(Number.isInteger)) { // <-- isInteger works with numbers
          return true
    }}
    return false
}

console.log(wrongValidatePIN('1234'))

A more suitable solution would be like this

    function validatePIN (pin) {
        var pinArray = pin.split(""); // <-- array of strings
        
        return (pinArray.length === 4 || pinArray.length === 6)
           && pinArray.every(char => !Number.isNaN(Number.parseInt(char, 10)))
    }

    console.log(validatePIN('1234'), validatePIN('123a'))

Alternatively, you could use regular expressions

function validatePin(pin) {
  return /^(\d{4}|\d{6})$/.test(pin)
}

console.log(validatePin('1234'), validatePin('123456'),
 validatePin('12345'), validatePin('123a'))

Answer 3

Answer №2

One way to optimize the code is by passing the isInteger function as an argument using pinArray.every(Number.isInteger) or providing it within a function using

.every(c=>Number.isInteger(c))

for concise code.

Keep in mind that using isInteger will check if the value is an actual integer, not if it can be parsed to one.

To potentially resolve this issue, consider using

pinArray.map(parseFloat).every(Number.isInteger);

or simply !pinArray.some(isNaN).

Here is a modified function that incorporates the mentioned changes:

function validatePIN (pin) {
    return (pin.length === 4 || pin.length === 6) 
        && ![...pin].some(isNaN);
}

It's worth noting that regular expressions could be a more suitable option for this type of check.

Answer 4

One way to optimize the code is by passing the isInteger function as an argument using pinArray.every(Number.isInteger) or providing it within a function using

.every(c=>Number.isInteger(c))

for concise code.

Keep in mind that using isInteger will check if the value is an actual integer, not if it can be parsed to one.

To potentially resolve this issue, consider using

pinArray.map(parseFloat).every(Number.isInteger);

or simply !pinArray.some(isNaN).

Here is a modified function that incorporates the mentioned changes:

function validatePIN (pin) {
    return (pin.length === 4 || pin.length === 6) 
        && ![...pin].some(isNaN);
}

It's worth noting that regular expressions could be a more suitable option for this type of check.

Answer 5

Answer №3

If you try to use pin.split("") with a number like 1234, it will not work. First, convert the number to a string and then split it using pin.toString().split("").

Within the .every() function, we need to change our string back to a number with +number.

return pinArray.every(number => Number.isInteger(+number));

.every() will give us either true or false.

See the functioning example below.

function validatePIN(pin) {
      var pinArray = pin.toString().split("");
      if (pinArray.length === 4 || pinArray.length === 6) {
        // gives true or false
        // +number changes string to number
        return pinArray.every(number => Number.isInteger(+number));
      }
      // Every PIN is considered invalid
      return false;
};
    
    
    console.log('test1', validatePIN(1234)); // true
    console.log('test2', validatePIN('1234')); // true
    console.log('test3', validatePIN('123a')); // false
    console.log('test4', validatePIN('0001')); // true

Answer 6

If you try to use pin.split("") with a number like 1234, it will not work. First, convert the number to a string and then split it using pin.toString().split("").

Within the .every() function, we need to change our string back to a number with +number.

return pinArray.every(number => Number.isInteger(+number));

.every() will give us either true or false.

See the functioning example below.

function validatePIN(pin) {
      var pinArray = pin.toString().split("");
      if (pinArray.length === 4 || pinArray.length === 6) {
        // gives true or false
        // +number changes string to number
        return pinArray.every(number => Number.isInteger(+number));
      }
      // Every PIN is considered invalid
      return false;
};
    
    
    console.log('test1', validatePIN(1234)); // true
    console.log('test2', validatePIN('1234')); // true
    console.log('test3', validatePIN('123a')); // false
    console.log('test4', validatePIN('0001')); // true

Utilizing Javascript's every() method to verify if all elements in an array are integers

Answer №1

Answer №2

Answer №3

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