KeyFreeQ

KeyFreeQ[assoc,form]

如果关联 assoc 中没有键匹配 form，给出 True，否则给出 False.

KeyFreeQ[form]

表示可以应用于表达式的 KeyFreeQ 的运算符形式.

范例

基本范例  (4)

检测 "x" 是否是关联中的键：

检测关联是否包含字符串的键：

KeyFreeQ 适用于规则列表：

判断哪个关联不包含键：

Wolfram Research (2015)，KeyFreeQ，Wolfram 语言函数，https://reference.wolfram.com/language/ref/KeyFreeQ.html.

文本

Wolfram Research (2015)，KeyFreeQ，Wolfram 语言函数，https://reference.wolfram.com/language/ref/KeyFreeQ.html.

CMS

Wolfram 语言. 2015. "KeyFreeQ." Wolfram 语言与系统参考资料中心. Wolfram Research. https://reference.wolfram.com/language/ref/KeyFreeQ.html.

APA

Wolfram 语言. (2015). KeyFreeQ. Wolfram 语言与系统参考资料中心. 追溯自 https://reference.wolfram.com/language/ref/KeyFreeQ.html 年

BibTeX

@misc{reference.wolfram_2024_keyfreeq, author="Wolfram Research", title="{KeyFreeQ}", year="2015", howpublished="\url{https://reference.wolfram.com/language/ref/KeyFreeQ.html}", note=[Accessed: 22-November-2024 ]}

BibLaTeX

@online{reference.wolfram_2024_keyfreeq, organization={Wolfram Research}, title={KeyFreeQ}, year={2015}, url={https://reference.wolfram.com/language/ref/KeyFreeQ.html}, note=[Accessed: 22-November-2024 ]}