deploy: 7c9208bfb3

api/json_pointer/front/index.md

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+# nlohmann::json_pointer::front
+
+```
+const string_t& front() const;
+```
+
+Return the first reference token.
+
+## Return value
+
+First reference token.
+
+## Exceptions
+
+Throws [out_of_range.405](https://json.nlohmann.me/home/exceptions/#jsonexceptionout_of_range405) if the JSON pointer has no parent.
+
+## Complexity
+
+Constant.
+
+## Examples
+
+Example
+
+The example shows the usage of `front`.
+
+```
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // different JSON Pointers
+    json::json_pointer ptr1("/foo");
+    json::json_pointer ptr2("/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:
+
+```
+first reference token of "/foo" is "foo"
+first reference token of "/foo/0" is "foo"
+```
+
+## Version history
+
+- Added in version 3.12.x.