One of the challenges when developing with Crystal is that it is not as forgiving about data types as, say, Python or Ruby.<\/p>\n
nil <\/strong>will keep you occupied.<\/p>\n The following error message:<\/p>\n can be solved by:<\/p>\n # cast to string, THEN check if it is nil \n(The above being a snipped from my internal application taxgod, which talks to the Shopify API \u2013 which will return JSON data, and some of this JSON data might be empty \/ nil.)<\/p>\n As the case is, use as_s? to cast the JSON::Any type to a string or nil, and then check whether it is nil. If it is not nil, then you can proceed with an as_s<\/strong> cast (which will raise if the underlying value is nil ), and set an alternative value if it is nil.<\/p>\n","protected":false},"excerpt":{"rendered":" Eine der Herausforderungen bei der Entwicklung mit Crystal ist, dass es nicht so nachsichtig mit Datentypen umgeht wie z.B. Python oder Ruby. nil wird Sie besch\u00e4ftigen. Die folgende Fehlermeldung: cast from Nil to String failed, at \/usr\/share\/crystal\/src\/json\/any.cr:220:5:220 kann wie folgt gel\u00f6st werden: # cast to string, DANN pr\u00fcfen, ob es nil ist, wenn...<\/p>","protected":false},"author":830,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"categories":[416],"tags":[409,477,800],"class_list":["post-27237","post","type-post","status-publish","format-standard","hentry","category-crystal-language","tag-crystal","tag-crystal-lang","tag-language"],"_links":{"self":[{"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/posts\/27237","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/users\/830"}],"replies":[{"embeddable":true,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/comments?post=27237"}],"version-history":[{"count":1,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/posts\/27237\/revisions"}],"predecessor-version":[{"id":27238,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/posts\/27237\/revisions\/27238"}],"wp:attachment":[{"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/media?parent=27237"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/categories?post=27237"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/tags?post=27237"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n
cast from Nil to String failed, at \/usr\/share\/crystal\/src\/json\/any.cr:220:5:220<\/h3>\n<\/blockquote>\n
\n
\nif !(shopify_data[spid][“billing_address”][“address2”].as_s? == nil)
name = shopify_data[spid][“billing_address”][“address2”].as_s
\nelse
name = “fallback_failed [taxgod]”
tg_info << “shopify_data[spid][\\”billing_address\\”][\\”address2\\”] for ” + spid + ” is nil ”
\nend<\/p>\n<\/blockquote>\n