The membership operators are used to validate the membership of a value. These operators are used to find out whether a value is a member of a sequence. The result of operation returns a Boolean value.
List of Blogger Membership Operators
| Operator | Meaning | Default syntax |
|---|---|---|
in | Found in | Operand in [ARRAY] |
| Operand in ( EXPRESSION ) | ||
contains | Include | [ARRAY] contains Operand |
| EXPRESSION contains operand | ||
| Functional Syntax | Operand operator ( Operand,Operand ) | |
Operand operator ( Operand operator Operand ) | ||
Operand operator ( Operand operator ( Operand operator Operand )) | ||
- Member operators always return a Boolean value.
- The Operand to be compared must be of the same type as the array, either String, Boolean or Number.
- The Operand to compare can be: An Blogger value, a dataset or the result of a Blogger Expression.
- The operation can be nested in another operation that accepts operand type of boolean.
- When ARRAY is a dataset of String, each must be wrapped with Double Quote: "STRING" and separeated by comma: "STRING","STRING".
Blogger Membership Operator Examples
OPERATOR "[IN]"
<b:eval expr='"Foo" in ["Foo","Bar","Baz"]'/>
The result of the operation will be: true since the string Foo is in the array.
OPERATOR "[CONTAINS]"
<b:eval expr='["Foo","Bar","Baz"] contains "Foo"'/>
The result will be: true since the array contains the string Foo. The result can be false if the dataset does not contain Foo.
OPERATOR "[CONTAINS]" WITH "[EXPRESSION]"
<b:if cond='data:post.body contains "Foo"'>
<!-- item -->
</b:if>
The output will be displayed if a word "Foo" is found inside post body.
NESTING IN A LOGICAL OPERATION
<b:eval expr='data:posts.size in [7,20,50] and data:view.isMultipleItems'/>
The operation result will be true if the current page contains 7 or 20 or 50 posts and the current page is a multi-posts page.
NESTING IN A LAMBDA OPERATION
<b:eval expr='data:posts count (p => p.labels any (l => l.name contains "Foo"))'/>
The operation will count a total number of label name contains "Foo" in the current page view.
NESTING IN A TERNARY OPERATION
<b:eval expr='data:view.search.label in ["Foo","Bar"] ? "Welcome to Label Foo" : "Welcome to Label Bar"'/>
If current page view is Label page Foo, "Welcome to Label Foo" will be shown, and if the current label page is Bar, "Welcome to Label Bar" will be displayed.
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