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

1 vote189 views1 answer
Status bar color android kotlin
Kotlin
2 votes177 views3 answers
Kotlin var val
Kotlin
0 vote131 views1 answer
Delete from sqlite android
Kotlin
0 vote197 views1 answer
Kotlin singleton
Kotlin
1 vote185 views1 answer
Length of array kotlin
Kotlin
8 votes389 views2 answers
Kotlin ternary
Kotlin
2 votes196 views1 answer
Kotlin read all inputstream
Kotlin
0 vote252 views3 answers
While loop kotlin
Kotlin
3 votes191 views2 answers
Viewmodelinject deprecated
Kotlin
2 votes185 views3 answers
Kotlin var and val
Kotlin