MongoDB MongoDB Query Language and Operators 3

Question 1

What does the $elemMatch operator do when used in a MongoDB query on an array field?

Accepted Answer

Matches documents where at least one array element satisfies all specified conditions

Answer

$elemMatch matches documents where at least one array element meets all conditions specified within the operator.

Question 2

What is the purpose of the $size operator in a MongoDB query?

Accepted Answer

Matches documents where an array field has the specified number of elements

Answer

$size matches arrays that have the exact number of elements specified.

Question 3

Which MongoDB query operator matches values that are greater than or equal to a specified value?

Accepted Answer

$gte

Answer

$gte (greater than or equal) matches documents where the field value is greater than or equal to the specified value.

Question 4

What does the $not operator do in a MongoDB query?

Accepted Answer

Inverts the effect of a single query expression

Answer

$not inverts the result of a query expression, returning documents that do not match the expression.

Question 5

Which operator performs a modulo operation on the value of a field in a MongoDB query?

Accepted Answer

$mod

Answer

$mod matches documents where the field value divided by a divisor has the specified remainder.

MongoDB Practice Test