IsEmpty()

Returns whether or not a given value is "empty".

The following data types can be checked:

  • Strings (a zero length string will return true)
  • Arrays (an array with no elements will return true)
  • Structs (a struct with no keys will return true)
  • Query (a query with no rows will return true)
IsEmpty( value=any );

Returns: Boolean

Argument Description
value
any, required

The value to check. Can be either a string, array, struct or query object.

Alias: object

Examples

The following statements all evaluate to true:

writeOutput('Strings');
writeDump(IsEmpty( '' )); // true;
writeDump(IsEmpty( ' ' )); // false;
writeDump(IsEmpty( '0' )); // false;
writeOutput('arrays');
writeDump(IsEmpty( [] )); // true;
writeDump(IsEmpty( [ 1, 2, 3 ] )); // false;
writeOutput('structs');
writeDump(IsEmpty( {} )); // true;
writeDump(IsEmpty( { key="value" } )); // false;
writeOutput('queries');
writeDump(IsEmpty( QueryNew( 'column' ) )); // true;
writeDump(IsEmpty( QueryNew( 'column', 'varchar', [ [ 'value' ] ] ) )); // false;
writeOutput('numerics always non-empty');
writeDump(IsEmpty( 0 )); // false;
writeDump(IsEmpty( 1 )); // false;
writeOutput('booleans always non-empty');
writeDump(IsEmpty( false )); // false;
writeDump(IsEmpty( true )); // false;

Warning

Prior to Lucee 4.5.1.016, IsEmpty( 0 ) and IsEmpty( false ) both returned true.

See also