KeyExistsQ

KeyExistsQ[assoc,key]

指定された key が連想 assoc 中にある場合はTrueを，その他の場合はFalseを返す．

KeyExistsQ[key]

式に適用可能なKeyExistsQの演算子形を表す．

詳細

例題

例  (2)

キーが連想中に存在するかどうか確かめる：

キーが規則のリスト中に存在するかどうか確かめる：

Wolfram Research (2014), KeyExistsQ, Wolfram言語関数， https://reference.wolfram.com/language/ref/KeyExistsQ.html.

テキスト

Wolfram Research (2014), KeyExistsQ, Wolfram言語関数， https://reference.wolfram.com/language/ref/KeyExistsQ.html.

CMS

Wolfram Language. 2014. "KeyExistsQ." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/KeyExistsQ.html.

APA

Wolfram Language. (2014). KeyExistsQ. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/KeyExistsQ.html

BibTeX

@misc{reference.wolfram_2024_keyexistsq, author="Wolfram Research", title="{KeyExistsQ}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/KeyExistsQ.html}", note=[Accessed: 17-November-2024 ]}

BibLaTeX

@online{reference.wolfram_2024_keyexistsq, organization={Wolfram Research}, title={KeyExistsQ}, year={2014}, url={https://reference.wolfram.com/language/ref/KeyExistsQ.html}, note=[Accessed: 17-November-2024 ]}