Shortcuts

Question 1

Run app in emulator

Answer 1

Shift F10

Question 2

Save all

Answer 2

Cntl S

Question 3

Comment 1 line

Answer 3

Ctnl /

Question 4

Comment multi lines

Answer 4

Ctnl Shift /

Question 5

Create function on custom method name()

Answer 5

Alt Shift Enter

Question 6

Reformat all selected code

Answer 6

Cntl Alt L

Question 7

What do the sizes mean sp vs dp

Answer 7

Sp = Scalable Pixels, text size is 36sp

Dp = Density Pixels, layout size

Question 8

How do you import images?

Answer 8

Resource manager > [+] > import Drawables

Question 9

How do you auto write the include libraries when you add code?

Answer 9

File > Settings > Editor > General > Auto import

Question 10

Include a val in text string?

Answer 10

Add $ before Val

E.g. “Your ${valName.funName} rest of text”

Question 11

Add param to a function. Int?

Answer 11

fun name(val nums: Int) {}

Question 12

Find item by resource ID?

Answer 12

val textValue = findViewById(R.string.string_name)

val myButton: Button = findViewById(R.id.button)

Question 13

How donyou set up a button click?

Answer 13

setOnClickListener

myButton.setOnClickListener { }

Question 14

Set text on a text view?

Answer 14

myTextView.text = “new text”

Question 15

Structure of if?

Answer 15

val num = 4
if (num > 4) {
 X
} else if (num == 4) {
 Y 
} else {
 Catch all }

Question 16

Structure of when?

Answer 16

when (myValue) {
 1 -> code
 2-> code 2
 else -> code n
}

Question 17

How does binding work?

Answer 17

Do it upfront, then don’t have to do lots of findById calls.

class MainActivity : AppCompatActivity(){

lateinit var binding: ActivityMainBinding

override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityMainBinding.inflate(layoutInflator)
setContentView(binding.root)
}
}

//ref by binding
myButton.text = "Click me"

Question 18

How are colurs used?

Answer 18

Colours.xml = #here's
Theme.xml = colour names

Question 19

Val or var for a mutable list?

Answer 19

Val as the reference to the actual list doesn’t change, just the contents.

Question 20

When to use while vs for loops?

Answer 20

For loops are quicker and more concise, no need for i++

for (name in names)