Slider widget in Flutter - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Slider widget in Flutter?

A Slider widget lets users select a value from a range by moving a thumb along a horizontal line. It is useful for choosing numbers like volume or brightness.

beginner

Which property of Slider controls the current selected value?

The value property holds the current position of the slider thumb, representing the selected value.

beginner

How do you update the Slider's value when the user moves the thumb?

Use the onChanged callback to get the new value and update the state variable that holds the slider's value.

beginner

What do the min and max properties of Slider do?

They set the minimum and maximum values the slider can select, defining the range of the slider.

intermediate

Can a Slider be disabled? How?

Yes, by setting onChanged to null, the Slider becomes disabled and the user cannot move the thumb.

What type of value does the Slider widget's value property expect?

A int

B double

C String

D bool

The Slider's value is a double because it can represent decimal numbers within the range.

Which callback is used to respond when the user moves the slider thumb?

A onChanged

B onPressed

C onTap

D onHover

The onChanged callback is called with the new value when the slider thumb moves.

How do you make a Slider inactive or disabled?

A Set min and max to the same value

B Set value to 0

C Set onChanged to null

D Set enabled property to false

Setting onChanged to null disables the Slider, preventing user interaction.

What happens if you set min to 0 and max to 100 in a Slider?

A Slider range is from 0 to 100

B Slider range is from 1 to 99

C Slider range is unlimited

D Slider will not work

The slider allows selecting any value between 0 and 100 inclusive.

Which widget is best to use for selecting a value by sliding horizontally?

A Checkbox

B Switch

C Radio

D Slider

Slider is designed for horizontal sliding to select a value from a range.

Explain how to create a basic Slider widget in Flutter that lets the user pick a value between 0 and 10.

Think about how to store the current value and update it when the user moves the slider.

Describe how you can disable a Slider and why you might want to do that.

Consider when you want to stop the user from changing the slider temporarily.