JavaScript looping through an array to check for numeric values

Question

I have an an array that returns the values such as the following:

//Eg 1    [ [ "214323", "34243" ], [ "3333", "123" ] ]

//Eg 2    [ [ "214323" ],[ "3333" ] ]

I want to validate if the array holds only numbers with no spaces or null, else I would like to throw an error. This is my following code and it does not work in the above example. It throws out an error even though all values are numeric.

for (var i = 0; i <= arrayVals.length; i++) {
    if(!(/^\d+$/.test(arrayVals[i]))) {
        err_comp=true;

        }   
}

if( err_comp ==true) {
        alert( 'The value has to be only numeric.');
}

João Silva · Accepted Answer · 2012-08-27 21:48:48Z

2

You have an array of arrays, thus you need two loops:

var err_comp = false;
for (var i = 0; i < arrayVals.length; i++) {
  var arr = arrayVals[i];
  for (var j = 0; j < arr.length; j++) {
    if (!(/^\d+$/.test(arr[j]))) {
        err_comp = true;
    }   
  }
}

Otherwise, you'd be testing /^\d+$/.test([ "214323", "34243" ]).

answered Aug 27, 2012 at 21:48

João Silva

91.8k29 gold badges156 silver badges158 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

mgraph · Accepted Answer · 2012-08-27 22:08:15Z

2

you should not use <= because you start with 0 you should use <:

for (var i = 0; i < arrayVals.length;

edited Aug 27, 2012 at 22:08

answered Aug 27, 2012 at 21:47

mgraph

15.3k4 gold badges43 silver badges76 bronze badges

1 Comment

Oriol Over a year ago

But isNaN won't throw any error with something like ' 10 ', but he doesn't want spaces.

João Silva · Accepted Answer · 2012-08-27 22:15:36Z

1

multi_arr.every(function(arr) {
    return arr.every(function(n) {
        return /^\d+$/.test(n);
    });
});

You can change the test as you need, and you can add a .every patch for IE8 if you want.

And you can make reusable your functions.

function forEveryArray(fn) {
    return function every_array(arr) {
        return arr.every(fn)
    }
}

function isNumber(n) { return /^\d+$/.test(n); }


multi_arr.every(forEveryArray(isNumber));

edited Aug 27, 2012 at 22:15

João Silva

91.8k29 gold badges156 silver badges158 bronze badges

answered Aug 27, 2012 at 21:53

gray state is coming

2,11711 silver badges20 bronze badges

2 Comments

João Silva Over a year ago

While it's a good solution, this won't work for versions of IE < 9.

gray state is coming Over a year ago

@João: That should be considered a feature, no? ;)

Collectives™ on Stack Overflow

JavaScript looping through an array to check for numeric values

3 Answers 3

Comments

1 Comment

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related