Touch input basics in Unity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the screen is touched.

Unity

if (Input.[1] > 0) {
    Debug.Log("Screen touched");
}

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AtouchPhase

Btouches

CtouchCount

DtouchPosition

Attempts:

3 left

💡 Hint

Common Mistakes

Using Input.touches instead of Input.touchCount

Using Input.touchPhase which is not a property of Input

The Input.touchCount property returns the number of touches currently on the screen.

2fill in blank

medium

Complete the code to get the position of the first touch on the screen.

Unity

Vector2 touchPos = Input.touches[[1]].position;

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A0

B1

C-1

DtouchCount

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 instead of 0 as index

Using touchCount as index which is out of range

The first touch is at index 0 in the Input.touches array.

3fill in blank

hard

Fix the error in the code to detect if the first touch just began.

Unity

if (Input.touches[0].[1] == TouchPhase.Began) {
    Debug.Log("Touch started");
}

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AtouchCount

Bphase

CdeltaPosition

Dposition

Attempts:

3 left

💡 Hint

Common Mistakes

Using position instead of phase

Using touchCount which is not a property of Touch

The phase property tells the current state of the touch, such as began, moved, or ended.

4fill in blank

hard

Fill both blanks to create a dictionary mapping fingerId to touch position for all touches.

Unity

var touchPositions = new Dictionary<int, Vector2>();
for (int i = 0; i < Input.touchCount; i++) {
    var touch = Input.touches[i];
    touchPositions[touch.[1]] = touch.[2];
}

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AfingerId

Bposition

Cphase

DdeltaPosition

Attempts:

3 left

💡 Hint

Common Mistakes

Using phase or deltaPosition instead of position

Using touchCount instead of fingerId

Each touch has a unique fingerId and a position on the screen.

5fill in blank

hard

Fill all three blanks to detect a swipe by checking if the touch moved more than 50 pixels.

Unity

if (Input.touchCount > 0) {
    Touch touch = Input.touches[[1]];
    if (touch.phase == TouchPhase.[2]) {
        if (touch.[3].magnitude > 50) {
            Debug.Log("Swipe detected");
        }
    }
}

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A0

BMoved

CdeltaPosition

DBegan

Attempts:

3 left

💡 Hint

Common Mistakes

Using phase Began instead of Moved

Using position instead of deltaPosition

Using wrong touch index

We check the first touch (index 0), see if it moved, and then check if the movement distance is greater than 50 pixels using deltaPosition.magnitude.