<ion-input> number input becomes null entering 2 "-" signs

[gerhartz]

I have a form with a number input but it breaks if the user enters 2 negative signs.

A. Entering “-20” gets saved to the form as “-20”
B. Entering 2 negative signs “–20” gets saved as null

1. Why is the user allowed the enter 2 negative signs when the input type is number? Shouldn’t it know that is not a proper format for numbers?

2. How can I make sure the user can’t enter two negative signs to break the input?

Form Input:

<ion-input
  formControlName="startTemperature"
  type="number"
></ion-input>

User Enters:

Form Value becomes null:

[ciccilleju]

You should use a regex to check the values typed by users.

1. Use Forms
2. Use a regex that fits your need
3. Show an error message in case of error (disabled the submit, alert message etc)

[rapropos]

My reading of this discussion suggests that one is better off pretending type="number" doesn’t exist, as it doesn’t seem to guarantee much of anything useful consistently across all browsers.