nlohmann::json_pointer::front¶

conststring_t&front()const;

Return the first reference token.

Return value¶

First reference token.

Exceptions¶

Throws out_of_range.405 if the JSON pointer has no parent.

Complexity¶

Constant.

Examples¶

Example

The example shows the usage of front.

#include<iostream>
#include<nlohmann/json.hpp>
usingjson=nlohmann::json;
intmain()
{
// different JSON Pointers
json::json_pointerptr1("/foo");
json::json_pointerptr2("/foo/0");
// call empty()
std::cout<<"first reference token of \""<<ptr1<<"\" is \""<<ptr1.front()<<"\"\n"
<<"first reference token of \""<<ptr2<<"\" is \""<<ptr2.front()<<"\""<<std::endl;
}

Output:

firstreferencetokenof"/foo"is"foo"
firstreferencetokenof"/foo/0"is"foo"

Version history¶

Added in version 3.12.x.