has method
The has()
method of the URLSearchParams interface returns a
boolean value that indicates whether the specified parameter is in the
search parameters.
A parameter name and optional value are used to match parameters.
If only a parameter name is specified, then the method will return true
if any parameters in the query string match the name, and false
otherwise.
If both a parameter name and value are specified, then the method will
return true
if a parameter matches both the name and value.
Implementation
external bool has(
String name, [
String value,
]);