- Qt 6.12
- Qt Quick
- QML Types
- DoubleValidator
- Qt 6.12.0 Reference Documentation

# DoubleValidator QML Type

Defines a validator for non-integer numbers. More...

Import Statement: | `import QtQuick`
In C++: | QDoubleValidator

- List of all members, including inherited members

## Properties

- bottom : real
- decimals : int
- locale : string
- notation : enumeration
- top : real

## Detailed Description

The DoubleValidator type provides a validator for non-integer numbers.

- Accepted Input: Input is accepted if it contains a double that is within the valid range and is in the correct format.
- Accepted but Invalid Input: Input is accepted but considered invalid if it contains a double that is outside the valid range or is in the wrong format (for example, too many digits after the decimal point or empty).
- Rejected Input: Input is rejected if it is not a double.

Note: If the valid range consists of only positive doubles (for example, 0.0 to 100.0) and the input is a negative double, it is rejected. If notation is set to `DoubleValidator.StandardNotation` and the input contains more digits before the decimal point than a double in the valid range may have, it is also rejected. If notation is `DoubleValidator.ScientificNotation` and the input is not in the valid range, it is accepted but invalid. The value may become valid by changing the exponent.

The following example shows a TextInput object with a DoubleValidator to check that the user has input a double within the specified range, updating the text color to highlight invalid input:

     import QtQuick

     TextInput {
         focus: true
         validator: DoubleValidator {
             bottom: 0.00
             top: 100.00
             decimals: 2
             notation: DoubleValidator.StandardNotation
         }
         onAcceptableInputChanged:
             color = acceptableInput ? "black" : "red";
     }

See also IntValidator, RegularExpressionValidator, and Validating Input Text.

## Property Documentation

### bottom : real

This property holds the validator's minimum acceptable value. By default, this property contains a value of -infinity.

### decimals : int

This property holds the validator's maximum number of digits after the decimal point. By default, this property contains a value of 1000.

### locale : string

This property holds the name of the locale used to interpret the number.

See also Qt.locale().

### notation : enumeration

This property holds the notation of how a string can describe a number.

The possible values for this property are:

Constant | Description
--- | ---
`DoubleValidator.StandardNotation` | only decimal numbers with optional sign (e.g. `-0.015`)
`DoubleValidator.ScientificNotation` | (default) the written number may have an exponent part (e.g. `1.5E-2`)

### top : real

This property holds the validator's maximum acceptable value. By default, this property contains a value of infinity.