Operator precedence in Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Kotlin code involving mixed operators?

Consider the following Kotlin code snippet:

val result = 3 + 4 * 2 / (1 - 5) % 2
println(result)

What will be printed?

Kotlin

val result = 3 + 4 * 2 / (1 - 5) % 2
println(result)

A 2

B 1

C 0

D 3

💡 Hint

Remember the order: parentheses, multiplication/division/modulus, then addition/subtraction.

First, (1 - 5) = -4.
Then, 4 * 2 = 8.
Next, 8 / -4 = -2.
Then, -2 % 2 = 0 (because -2 mod 2 is 0 in Kotlin).
Finally, 3 + 0 = 3.

❓ Predict Output

intermediate

What is the value of x after this Kotlin expression?

Given this Kotlin code:

var x = 10
x += 3 * 2 - 4 / 2

What is the value of x after running this?

Kotlin

var x = 10
x += 3 * 2 - 4 / 2
println(x)

A 15

B 16

C 14

D 17

💡 Hint

Calculate multiplication and division before addition and subtraction.

3 * 2 = 6
4 / 2 = 2
Then 6 - 2 = 4
x += 4 means x = 10 + 4 = 14

❓ Predict Output

advanced

What does this Kotlin code print with logical and arithmetic operators?

Analyze this Kotlin code:

val a = true
val b = false
val c = 5
val d = 10
val result = a && b || c < d && !b
println(result)

What is the output?

Kotlin

val a = true
val b = false
val c = 5
val d = 10
val result = a && b || c < d && !b
println(result)

A false

B true

C Compilation error

D Runtime exception

💡 Hint

Remember that && has higher precedence than ||, and ! has highest precedence.

!b = !false = true
a && b = true && false = false
c < d = 5 < 10 = true
c < d && !b = true && true = true
Then false || true = true

❓ Predict Output

advanced

What is the output of this Kotlin code with mixed increment and arithmetic?

Consider this Kotlin snippet:

var x = 5
val y = x++ * 2 + --x
println(y)

What will be printed?

Kotlin

var x = 5
val y = x++ * 2 + --x
println(y)

A 15

B 23

C 29

D 25

💡 Hint

Remember post-increment returns the value before increment, pre-decrement decrements before use.

Initial x=5
x++ returns 5, then x becomes 6
--x decrements x to 5, then returns 5
So y = 5 * 2 + 5 = 10 + 5 = 15

❓ Predict Output

expert

What is the output of this Kotlin code with chained assignments and operator precedence?

Analyze this Kotlin code:

var a = 2
var b = 3
var c = 4
val result = a + b * c / a - b % c
println(result)

What will be printed?

Kotlin

var a = 2
var b = 3
var c = 4
val result = a + b * c / a - b % c
println(result)

A 5

B 7

C 6

D 4

💡 Hint

Follow operator precedence: multiplication/division/modulus before addition/subtraction.

b * c = 3 * 4 = 12
12 / a = 12 / 2 = 6
b % c = 3 % 4 = 3
Then a + 6 - 3 = 2 + 6 - 3 = 5