Appends a new name-value pair to the query string.
name
The name of the parameter
value
The value of the parameter
let params = new URLSearchParams("foo=1")
params.append("foo", "2")
params.toString()
"foo=1&foo=2"
let params = new URLSearchParams()
params.append("test", "value")
params.toString()
"test=value"
let params = new URLSearchParams("a=1")
params.append("b", "2")
params.toString()
"a=1&b=2"