Kotlin Null Safety

Null check in kotlin

if(a != null)  {
//do something
}

Kotlin Null Safety

// Variable types in Kotlin don't allow the assignment of null. 
// Declare a nullable varible by adding ? at the end of its type.
var neverNull: String = "This can't be null"            
neverNull = null                                        // Error
var nullable: String? = "You can keep a null here"      
nullable = null                                         // Ok
var inferredNonNull = "The compiler assumes non-null"   
inferredNonNull = null                                  // Error
fun strLength(notNull: String): Int {                   
    return notNull.length
}
strLength(neverNull)                                    // Ok
strLength(nullable)                                     // Error

Source: play.kotlinlang.org

Similar codes

0 vote205 views1 answer
Copy function in kotlin not working with livedata
Kotlin
0 vote211 views1 answer
Pip system path windows environment
Kotlin
0 vote228 views1 answer
Set text size programmatically android kotlin
Kotlin
0 vote213 views3 answers
Kotlin deque
Kotlin
0 vote285 views1 answer
Android prevent screenshot in activity
Kotlin
1 vote292 views1 answer
Android studio kotlin
Kotlin
1 vote226 views1 answer
Koltin measureTimeMillis
Kotlin
0 vote204 views1 answer
Kotlin http request
Kotlin
1 vote209 views1 answer
Run kotlin in terminal
Kotlin
0 vote230 views1 answer
Button kotlin
Kotlin