How can you safely call a function printLength that prints the length of a nullable String text without causing a NullPointerException?

hard📝 Application Q15 of 15

Kotlin - Null Safety

How can you safely call a function printLength that prints the length of a nullable String text without causing a NullPointerException?

Afun printLength(text: String) { println(text.length) } printLength(null)

Bfun printLength(text: String?) { println(text.length) } printLength(null)

Cfun printLength(text: String?) { println(text?.length ?: 0) } printLength(null)

Dfun printLength(text: String) { println(text?.length) } printLength(null)

Step-by-Step Solution

Solution:

Step 1: Understand function parameter nullability
To accept null, parameter must be String?. Options A and D use non-nullable String, so passing null causes error.
Step 2: Use safe call and default value
fun printLength(text: String?) { println(text?.length ?: 0) } printLength(null) uses safe call ?. and Elvis operator ?: to print 0 if text is null, avoiding exceptions.
Final Answer:
fun printLength(text: String?) { println(text?.length ?: 0) } printLength(null) -> Option C
Quick Check:
Safe call + Elvis handles null safely [OK]

Quick Trick: Use ?. and ?: to safely handle nullable parameters [OK]

Common Mistakes:

MISTAKES

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