isNullOrBlank

isNullOrBlank is a function in the Kotlin standard library that extends the nullable CharSequence type. It returns a Boolean indicating whether the receiver is null or contains only whitespace characters.

For non-null strings, isNullOrBlank delegates to isBlank to determine if the string is empty or consists solely of whitespace; whitespace characters include spaces, tabs, newlines, and other Unicode whitespace. This makes the function useful for validating input where blank values should be treated as absent.

The function is defined as CharSequence?.isNullOrBlank(): Boolean in the kotlin.text package and pairs with isNullOrEmpty, which returns true for null or empty strings but does not treat whitespace-only strings as blank.

Examples: null.isNullOrBlank() returns true; "".isNullOrBlank() returns true; " ".isNullOrBlank() returns true; "Kotlin".isNullOrBlank() returns false.

Usage: It is commonly used in input validation and data parsing to quickly guard against null or blank values without risking null pointer exceptions. The function simplifies checks by consolidating nullability and blankness into a single predicate, improving readability in common data-handling scenarios.