Node.js is an open-source project widely used for the development of dynamic web applications. The URLSearchParams API in Node.js allows read and write operations on the URL query.
The URLSearchParams class is a global object and used with one of the four following constructors.
Constructors:
- new URLSearchParams(): No argument constructor instantiates a new empty URLSearchParams object.
- new URLSearchParams(string): Accepts a string as an argument to instantiate a new URLSearchParams object.
Output:
abc
xyz
- new URLSearchParams(obj): Accepts an object with a collection of key-value pairs to instantiate a new URLSearchParams object. The key-value pair of obj are always coerced to strings. Duplicate keys are not allowed.
Output:
user=ana&course=math%2Cchem%2Cphys
- new URLSearchParams(iterable): Accepts an iterable object having a collection of key-value pairs to instantiate a new URLSearchParams object. Iterable can be any iterable object. Since URLSearchParams is iterable, an iterable object can be another URLSearchParams, where the constructor will create a clone of the provided URLSearchParams. Duplicate keys are allowed.
Output:
West+Bengal=Kolkata&Karnataka=Bengaluru
Accessing the URL query:
- urlSearchParams.get(name): Returns the value of the first name-value pair that matches with the argument passed. If no such pair exists, null is returned.
Output:
123
- urlSearchParams.getAll(name): Returns all the value of the name-value pair that matches with the argument passed. If no such pair exists, null is returned.
Output:
[ '123', '526' ]
- urlSearchParams.has(name): Returns true if the argument passed matches with any existing name of the name-value pair else returns false.
Output:
true
false
Manipulating the URL query:
- urlSearchParams.set(name, value): Sets the value in the URLSearchParams object associated with name to the specified value. If more than one name-value pairs exists, whose names are same as the 'name' argument, then the only value of first matching pair is changed, rest all are removed.
Output:
abc=123&xyz=526&abc=258
abc=opq&xyz=526
- urlSearchParams.append(name, value): Appends a new name-value pair to the existing URLSearchParams query.
Output:
xyz=123&foo=789&xyz=zoo&foo=def
- urlSearchParams.delete(name): Removes all name-value pairs whose name is same as 'name' argument.
Output:
xyz=123&foo=789&xyz=zoo&foo=def
xyz=123&xyz=zoo
- urlSearchParams.sort(): Sorts the existing name-value pairs in-place by their names using a stable sorting algorithm.
Output:
abc=programs&query=node&type=search
- urlSearchParams.toString(): Returns the URL search parameters as a string, with characters percent-encoded wherever necessary.
Output:
query=node&type=search&passwd%5B%5D=3456
Iterating the URL query:
- urlSearchParams.entries(): Returns an iterator over the entry set of the param object.
Output:
query-->node
type-->search
passwd-->3456
- urlSearchParams.keys(): Returns an iterator over the key set of the param object.
Output:
query
type
passwd
- urlSearchParams.values(): Returns an iterator over the value set of the param object.
Output:
node
search
3456
- urlSearchParams.forEach(fn[, arg]): fn is a function invoked for each name-value pair in the query and arg is an object to be used when 'fn' is called. It iterates over each name-value pair in the query and invokes the function.
Output:
a b true
c d true
d z true
- urlSearchParams[Symbol.iterator]():
Output:
firstname john
lastname beck
gender male
