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 vote143 views1 answer
Kotlin string to float
Kotlin
4 votes160 views3 answers
How to set layout params in android programmatically
Kotlin
1 vote132 views1 answer
Typeerror: undefined is not an object (evaluating
Kotlin
1 vote142 views2 answers
Glide vs picasso
Kotlin
0 vote165 views1 answer
Kotlin to sorted map reverse
Kotlin
0 vote129 views1 answer
RecyclerView heights decrease on scroll
Kotlin
2 votes139 views1 answer
Kotlin read all bytes from inputstream
Kotlin
0 vote146 views2 answers
Kotlin enum
Kotlin
5 votes171 views2 answers
Thread in kotlin
Kotlin
7 votes255 views6 answers
Kotlin loop until
Kotlin