Advanced Features of the [[ Operator

Logical operations in the [[ operator

We can use logical operations AND, OR, and NOT in the [[ operator. They combine several boolean expressions into a single condition. The following table explains how they work.

Operation	Description	Example
&&	Logical AND	[[ -n "$var" && "$var" < "abc" ]] && echo "The string is not empty and it is smaller than \"abc\""
||	Logical OR	[[ "abc" < "$var" \|\| -z "$var" ]] && echo "The string is larger than \"abc\" or it is empty"
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