The value of ng-model is consistently stored as a string, regardless of whether the input is a number or

Question

The value of ng-model is consistently stored as a string, regardless of whether the input is a number or

<div>
<input type="text" ng-model="test"/>
</div>

When a value is entered into the input field with the ng-model "test", it is always treated as a String type, even if it is a valid number. However, I am looking for a way to determine the exact data type of the entered value.

Is there a method to identify the data type of the entered value? For example, if the value entered is a number, the data type should be "Number", and if the value entered is "Abc", the data type should be "String", and so on.

In summary, I need to keep the same HTML structure but be able to determine the data type of the value entered.

javascript angularjs

Answer 1

Answer №1

If you want a helpful response, make sure to provide a snippet of code for reference. Without it, it might be challenging to give you the answer you need. It seems like the issue could be related to incorrect HTML, such as:

<input type="text" />

The code above will output a 'string'.

<input type="number" />

With the above code, you will get a 'number'. Have you validated your code correctly?

Update: If you find yourself using <input> without specifying the 'type' attribute (invalid HTML), you can verify the type in your controller when handling the data. For example, using lodash:

if (_.isString(value)) { }
if (_.isNumber(value)) { }

Alternatively, in pure JavaScript, you can use 'typeof'.

Another approach could be to perform a RegEx check in your controller if you are limited to using type="text" only, specifically searching for numbers within the incoming string.

if (value.match(/^\d+$/)) {
  // This should be treated as a 'number';
}

Answer 2

If you want a helpful response, make sure to provide a snippet of code for reference. Without it, it might be challenging to give you the answer you need. It seems like the issue could be related to incorrect HTML, such as:

<input type="text" />

The code above will output a 'string'.

<input type="number" />

With the above code, you will get a 'number'. Have you validated your code correctly?

Update: If you find yourself using <input> without specifying the 'type' attribute (invalid HTML), you can verify the type in your controller when handling the data. For example, using lodash:

if (_.isString(value)) { }
if (_.isNumber(value)) { }

Alternatively, in pure JavaScript, you can use 'typeof'.

Another approach could be to perform a RegEx check in your controller if you are limited to using type="text" only, specifically searching for numbers within the incoming string.

if (value.match(/^\d+$/)) {
  // This should be treated as a 'number';
}

Answer 3

Answer №2

To determine if a string is a number, you will need to develop your own function unless you are already utilizing a library with a comparable function.

One way to achieve this is by creating a custom function like the following:

function isNumber(string) {
  var float = parseFloat(string);

  return !isNaN(float) && float.toString().length === string.length;
}

console.log(isNumber('365'));          // true
console.log(angular.isNumber('365'));  // false
console.log(typeof '365');             // string
console.log(typeof parseFloat('365')); // number
console.log(isNaN(parseFloat('365'))); // false

console.log(isNumber('365 days in a year'));          // false
console.log(angular.isNumber('365 days in a year'));  // false
console.log(typeof '365 days in a year');             // string
console.log(typeof parseFloat('365 days in a year')); // number
console.log(isNaN(parseFloat('365 days in a year'))); // false

console.log(isNumber('There are 365 days in a year'));          // false
console.log(angular.isNumber('There are 365 days in a year'));  // false
console.log(typeof 'There are 365 days in a year');             // string
console.log(typeof parseFloat('There are 365 days in a year')); // number
console.log(isNaN(parseFloat('There are 365 days in a year'))); // true

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

update: I have developed a basic function to validate if a value is a number and do not rely on angular.isNumber.

Answer 4

To determine if a string is a number, you will need to develop your own function unless you are already utilizing a library with a comparable function.

One way to achieve this is by creating a custom function like the following:

function isNumber(string) {
  var float = parseFloat(string);

  return !isNaN(float) && float.toString().length === string.length;
}

console.log(isNumber('365'));          // true
console.log(angular.isNumber('365'));  // false
console.log(typeof '365');             // string
console.log(typeof parseFloat('365')); // number
console.log(isNaN(parseFloat('365'))); // false

console.log(isNumber('365 days in a year'));          // false
console.log(angular.isNumber('365 days in a year'));  // false
console.log(typeof '365 days in a year');             // string
console.log(typeof parseFloat('365 days in a year')); // number
console.log(isNaN(parseFloat('365 days in a year'))); // false

console.log(isNumber('There are 365 days in a year'));          // false
console.log(angular.isNumber('There are 365 days in a year'));  // false
console.log(typeof 'There are 365 days in a year');             // string
console.log(typeof parseFloat('There are 365 days in a year')); // number
console.log(isNaN(parseFloat('There are 365 days in a year'))); // true

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

update: I have developed a basic function to validate if a value is a number and do not rely on angular.isNumber.

The value of ng-model is consistently stored as a string, regardless of whether the input is a number or

Answer №1

Answer №2

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