$Root element
$.fieldDirect child field
$.field.subfieldNested field
$['field']Bracket notation
$.field[0]First array element
$.field[-1]Last array element
$.field[*]All array elements
$.field[1,2]Multiple indices
$.field[0:2]Slice (exclusive)
$..fieldRecursive descent (any depth)
$.*All child fields
$.field.*All children of field
$.[?(@.age>18)]Filter by condition
$.[?(@.price>100 && @.price<500)]Multiple conditions
$.[?(@.category=='book')]String comparison
$..[?(@.active)]Filter truthy values
$.field.length()Array length
$.field.sum()Sum of numbers
$..field.min()Minimum value
$..field.max()Maximum value
$..field.avg()Average value
$.field.[@.size>100]Nested filter