"null pointer" meaning in English

{
  "forms": [
    {
      "form": "null pointers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "null pointer (plural null pointers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Computing",
          "orig": "en:Computing",
          "parents": [
            "Technology",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A pointer that does not point to any data object."
      ],
      "id": "en-null_pointer-en-noun-8NczY~S~",
      "links": [
        [
          "computing",
          "computing#Noun"
        ],
        [
          "pointer",
          "pointer"
        ],
        [
          "data object",
          "data object"
        ]
      ],
      "raw_glosses": [
        "(computing) A pointer that does not point to any data object."
      ],
      "topics": [
        "computing",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "sciences"
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "pointer that does not point to any data object",
          "word": "nollaosoitin"
        },
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "pointer that does not point to any data object",
          "word": "tyhjä osoitin"
        },
        {
          "code": "de",
          "lang": "German",
          "sense": "pointer that does not point to any data object",
          "tags": [
            "masculine"
          ],
          "word": "Nullzeiger"
        },
        {
          "code": "de",
          "lang": "German",
          "sense": "pointer that does not point to any data object",
          "tags": [
            "masculine"
          ],
          "word": "Null-Zeiger"
        },
        {
          "code": "is",
          "lang": "Icelandic",
          "sense": "pointer that does not point to any data object",
          "tags": [
            "masculine"
          ],
          "word": "tómabendir"
        },
        {
          "code": "ja",
          "lang": "Japanese",
          "roman": "nurupointa",
          "sense": "pointer that does not point to any data object",
          "word": "ヌルポインタ"
        },
        {
          "code": "ja",
          "lang": "Japanese",
          "roman": "nurupo",
          "sense": "pointer that does not point to any data object",
          "word": "ぬるぽ"
        },
        {
          "code": "ru",
          "lang": "Russian",
          "roman": "nulevój ukazátelʹ",
          "sense": "pointer that does not point to any data object",
          "tags": [
            "masculine"
          ],
          "word": "нулево́й указа́тель"
        },
        {
          "code": "sv",
          "lang": "Swedish",
          "sense": "pointer that does not point to any data object",
          "tags": [
            "common-gender"
          ],
          "word": "nullpekare"
        }
      ],
      "wikipedia": [
        "null pointer"
      ]
    }
  ],
  "word": "null pointer"
}

{
  "forms": [
    {
      "form": "null pointers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "null pointer (plural null pointers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Computing"
      ],
      "glosses": [
        "A pointer that does not point to any data object."
      ],
      "links": [
        [
          "computing",
          "computing#Noun"
        ],
        [
          "pointer",
          "pointer"
        ],
        [
          "data object",
          "data object"
        ]
      ],
      "raw_glosses": [
        "(computing) A pointer that does not point to any data object."
      ],
      "topics": [
        "computing",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "sciences"
      ],
      "wikipedia": [
        "null pointer"
      ]
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "pointer that does not point to any data object",
      "word": "nollaosoitin"
    },
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "pointer that does not point to any data object",
      "word": "tyhjä osoitin"
    },
    {
      "code": "de",
      "lang": "German",
      "sense": "pointer that does not point to any data object",
      "tags": [
        "masculine"
      ],
      "word": "Nullzeiger"
    },
    {
      "code": "de",
      "lang": "German",
      "sense": "pointer that does not point to any data object",
      "tags": [
        "masculine"
      ],
      "word": "Null-Zeiger"
    },
    {
      "code": "is",
      "lang": "Icelandic",
      "sense": "pointer that does not point to any data object",
      "tags": [
        "masculine"
      ],
      "word": "tómabendir"
    },
    {
      "code": "ja",
      "lang": "Japanese",
      "roman": "nurupointa",
      "sense": "pointer that does not point to any data object",
      "word": "ヌルポインタ"
    },
    {
      "code": "ja",
      "lang": "Japanese",
      "roman": "nurupo",
      "sense": "pointer that does not point to any data object",
      "word": "ぬるぽ"
    },
    {
      "code": "ru",
      "lang": "Russian",
      "roman": "nulevój ukazátelʹ",
      "sense": "pointer that does not point to any data object",
      "tags": [
        "masculine"
      ],
      "word": "нулево́й указа́тель"
    },
    {
      "code": "sv",
      "lang": "Swedish",
      "sense": "pointer that does not point to any data object",
      "tags": [
        "common-gender"
      ],
      "word": "nullpekare"
    }
  ],
  "word": "null pointer"
}