Kotlin X vs Y

JVM and multiplatform language from JetBrains.All Kotlin pages

Kotlin let vs apply vs also vs run vs with: scope functions comparedKotlin scope functions differ in two ways: the object is it or this, and they return the object or the block result. When to use let, apply, also, run and with.
Kotlin val vs var: read-only vs mutable variablesIn Kotlin, val declares a read-only reference assigned once and var a mutable one. A val object can still change inside. When to use each one, and const val.