{"id":1190,"date":"2008-01-31T16:42:58","date_gmt":"2008-01-31T07:42:58","guid":{"rendered":"http:\/\/blog.tksk.net\/?p=1190"},"modified":"2008-01-31T16:42:58","modified_gmt":"2008-01-31T07:42:58","slug":"lets-linq-0","status":"publish","type":"post","link":"https:\/\/blog.tksk.net\/?p=1190","title":{"rendered":"Let’s Linq [0]"},"content":{"rendered":"

\u3068\u306b\u304b\u304f\u5e03\u6559\u3057\u305f\u3044\u6c17\u5206\u306a\u306e\u3067\u3002\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3068\u3044\u3046\u5bfe\u8c61\u306b\u5bfe\u3057\u3066\u3001\u7d14\u7c8b\u306b\u9762\u767d\u3044\u3068\u611f\u3058\u3066\u308b\u306e\u306f\u4e45\u3057\u3076\u308a\u306a\u306e\u3067\u3002<\/p>\n

\u4f8b\u306e\u3054\u3068\u304f\u3001C#3.0\u3002\u305d\u306e\u697d\u3057\u3055\u3092\u55a7\u4f1d\u3057\u305f\u3044\u3060\u3051\u3067\u3042\u3063\u3066\u3001\u5165\u9580\u3068\u8a00\u3048\u308b\u3088\u3046\u306a\u6574\u7136\u3068\u3057\u305f\u3082\u306e\u3058\u3083\u3042\u306a\u3044\u306e\u3067\u3002\u5ff5\u306e\u305f\u3081\u3002(\u305d\u308c\u3067\u3082\u3053\u3053\u6570\u65e5\u306e\u5185\u5bb9\u3088\u308a\u306f\u300c\u305d\u308c\u5411\u304d\u300d)<\/p>\n

var vals = new[] { 1, 2, 3 };<\/p><\/blockquote>\n

C#3.0\u304b\u3089\u6697\u9ed9\u306e\u578b\u5ba3\u8a00\u3092\u793a\u3059var\u30ad\u30fc\u30ef\u30fc\u30c9\u304c\u5165\u3063\u305f\u3002\u3068\u3053\u308d\u3067\u3001\u4e0a\u8a18\u306e\u30b3\u30fc\u30c9\u306b\u306f\u5b9f\u306f2\u56de\u300c\u6697\u9ed9\u300d\u304c\u4f7f\u308f\u308c\u3066\u3044\u308b\u3002var \u3068\u914d\u5217\u306e\u521d\u671f\u5316\u90e8\u5206\u3002\u307e\u305a\u6700\u521d\u306b\u3001\u4e0e\u3048\u3066\u308b\u521d\u671f\u5024\u306f int\u578b\u5909\u6570\u7fa4\u3060\u304b\u3089\u3001\u3053\u3044\u3064\u306fint\u578b\u914d\u5217\u306b\u9055\u3044\u306a\u3044\u3088\u306d\u3001\u3063\u3066\u3044\u3046\u300c\u6697\u9ed9\u300d\u304c\u50cd\u3044\u3066\u308b\u3002\u305d\u3057\u3066\u3001\u4ee3\u5165\u306e\u53f3\u8fba\u304c\u6c7a\u307e\u308c\u3070\u3001\u305d\u308c\u3092\u53d7\u3051\u308b\u5074\u306e\u578b\u3082\u81ea\u305a\u3068\u6c7a\u307e\u3063\u3066\u304f\u308b\u3002\u3064\u307e\u308a\u3001var \u306f int[] \u306b\u306a\u308b\u3063\u3066\u308f\u3051\u3002<\/p>\n

\u307e\u3042\u3053\u308c\u306f\u3001\u300c\u3042\u3042\u3061\u3087\u3063\u3068\u4fbf\u5229\u304b\u3082\u306d\u300d\u3063\u3066\u3044\u3046\u6a5f\u80fd\u62e1\u5f35\u3002\u4eca\u5ea6\u306f\u3001\u62e1\u5f35\u30e1\u30bd\u30c3\u30c9(\u300c\u62e1\u5f35\u5b50\u300d\u3068\u3082\u3002\u4ffa\u306f\u300c-\u5b50\u300d\u306e\u547c\u79f0\u306f\u5acc\u3044<\/strong>) \u3092\u4f7f\u3046\u3002\u66f8\u304d\u65b9\u306a\u3069\u306e\u8a73\u7d30\u306f\u8abf\u3079\u3066\u3082\u3089\u3046\u3068\u3057\u3066\u3001\u8981\u3059\u308b\u306b\u3053\u308c\u306f\u65e2\u5b58\u306e\u30af\u30e9\u30b9\u306b\u30e1\u30bd\u30c3\u30c9\u3092\u5f8c\u4ed8\u3067\u8ffd\u52a0\u3059\u308b\u6a5f\u80fd\u3060\u3002\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u985e(IEnumerable<T> \u3092\u5b9f\u88c5\u3057\u3066\u308b\u306e\u3092\u4fbf\u5b9c\u4e0a\u3053\u3046\u547c\u3076\u3053\u3068\u306b\u3059\u308b) \u306e\u305f\u3081\u306b\u8c4a\u5bcc\u306b\u62e1\u5f35\u30e1\u30bd\u30c3\u30c9\u304c\u7528\u610f\u3055\u308c\u3066\u3044\u308b\u306e\u3067\u3001\u305d\u3044\u3064\u3092\u4f7f\u3063\u3066\u307f\u308b\u3002<\/p>\n

var avg = vals.Average();<\/p><\/blockquote>\n

\u3092\u3084\u308b\u3068\u3001avg \u306b\u306f vals \u306e\u5e73\u5747\u3001\u3064\u307e\u308a2.0(double \u3067\u8fd4\u3063\u3066\u304f\u308b)\u304c\u5165\u308b\u308f\u3051\u3002\u3067\u3001\u6b21\u306e\u4f8b\u3092\u8003\u3048\u3066\u307f\u308b\u3002<\/p>\n

var strs = new[] { “a”, “bc”, “def”\u00a0};
\nvar avg = strs.Average();<\/p><\/blockquote>\n

\u3069\u3046\u306a\u308b\u3060\u308d\u3046\u304b? \u7b54\u3048\u3001\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u308b\u3002\u305d\u3082\u305d\u3082\u300c\u5e73\u5747\u300d\u3063\u3066\u306e\u306f\u6570\u5024\u5316\u3055\u308c\u306a\u3044\u3082\u306e\u306b\u306f\u9069\u7528\u3067\u304d\u306a\u3044\u6f14\u7b97\u3067\u3042\u308b\u3002\u3060\u304b\u3089\u3001\u5f53\u7136\u306e\u3054\u3068\u304f\u6587\u5b57\u5217\u306e\u96c6\u5408\u306b\u5bfe\u3057\u3066\u300c\u5e73\u5747\u300d\u306f\u8a08\u7b97\u3067\u304d\u306a\u3044\u3057\u3001\u305d\u3046\u3057\u305f\u62e1\u5f35\u30e1\u30bd\u30c3\u30c9\u306e\u30aa\u30fc\u30d0\u30ed\u30fc\u30c9\u3082\u7528\u610f\u3055\u308c\u3066\u3044\u306a\u3044\u3002<\/p>\n

\u305d\u308c\u3067\u306f\u3001\u300c\u6587\u5b57\u5217\u306e\u96c6\u5408\u306b\u5bfe\u3059\u308b\u6f14\u7b97\u300e\u5e73\u5747\u300f\u3068\u306f\u3001\u96c6\u5408\u306e\u5404\u8981\u7d20\u306e\u9577\u3055\u306e\u76f8\u52a0\u5e73\u5747\u3067\u3042\u308b\u300d\u3063\u3066\u3044\u3046\u5b9a\u7fa9\u304c\u3042\u3063\u305f\u3089\u3069\u3046\u3060\u308d\u3046\u3002\u305d\u306e\u5b9a\u7fa9\u306b\u5408\u3046\u3088\u3046\u306b\u300c\u6587\u5b57\u5217\u300d\u304b\u3089\u300c\u9577\u3055\u300d\u3092\u53d6\u308a\u51fa\u3059\u30e1\u30bd\u30c3\u30c9\u3092\u7528\u610f\u3057\u3066\u3084\u308c\u3070\u3001\u3053\u3053\u3067\u5b9a\u7fa9\u3059\u308b\u5e73\u5747\u306f\u8a08\u7b97\u53ef\u80fd\u306b\u306a\u308b\u3002\u5b9f\u306f\u3001 Average() \u306b\u306f\u3061\u3083\u3093\u3068\u305d\u3046\u3057\u305f\u9700\u8981\u3092\u6e80\u305f\u3059\u30aa\u30fc\u30d0\u30ed\u30fc\u30c9\u304c\u7528\u610f\u3055\u308c\u3066\u308b\u3002\u8a00\u3063\u3066\u3057\u307e\u3046\u3068\u3001 Average(Func<string, int> selector) \u3092\u4f7f\u3048\u3070\u3088\u3044\u3002<\/p>\n

\u3053\u3053\u3067\u3001 Func<string, int> \u304c\u521d\u3081\u3066\u51fa\u3066\u304d\u305f\u3002\u3053\u308c\u306f\u3001string\u3092\u5f15\u6570\u306b\u53d6\u308a\u3001int\u3092\u8fd4\u3059\u30e1\u30bd\u30c3\u30c9\u3092\u793a\u3059\u3002\u305d\u3053\u3067\u3001\u6b21\u306e\u3088\u3046\u306a\u30e1\u30bd\u30c3\u30c9\u3092\u7528\u610f\u3057\u3066\u3084\u308b\u3068\u3001<\/p>\n

int getlen(string str)
\n{
\n\u00a0\u00a0\u00a0 return str.Length;
\n}<\/p><\/blockquote>\n

Average() \u306e\u5f15\u6570\u306b\u3053\u306e getlen \u3092\u6e21\u3059\u3053\u3068\u304c\u3067\u304d\u308b\u3002\u3064\u307e\u308a\u3001<\/p>\n

var strs = new[] { “a”, “bc”, “def”\u00a0};
\nvar avg = strs.Average((Func<string, int>) getlen);<\/p><\/blockquote>\n

\u3068\u3059\u308b\u3053\u3068\u3067\u3001\u5148\u306e\u5b9a\u7fa9\u306b\u6cbf\u3046\u300c\u5e73\u5747\u5024\u300d\u304c\u5f97\u3089\u308c\u308b\u308f\u3051\u3060\u3002\u3053\u3053\u3067\u3001getlen() \u306e\u95a2\u6570(\u4f55\u304b\u5024\u3092\u6e21\u3057\u3066\u3001\u5225\u306e\u5024\u3092\u53d6\u308a\u51fa\u3059\u88c5\u7f6e)\u3068\u3057\u3066\u306e\u6a5f\u80fd\u306b\u7740\u76ee\u3059\u308b\u3002\u3059\u308b\u3068\u3001\u5b9f\u8cea\u7684\u306b\u306f str.Length \u306e\u90e8\u5206\u3057\u304b\u91cd\u8981\u3067\u306a\u3044\u3053\u3068\u304c\u308f\u304b\u308b\u3002\u5b9f\u306f\u3001C#3.0 \u3067\u306f\u3001\u4e0a\u8a18\u306e\u30b3\u30fc\u30c9\u3092\u6b21\u306e\u3088\u3046\u306b\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u308b\u3002<\/p>\n

var strs = new[] { “a”, “bc”, “def”\u00a0};
\nvar avg = strs.Average(str => str.Length);<\/p><\/blockquote>\n

\u3053\u308c\u306f\u30e9\u30e0\u30c0\u5f0f\u3068\u547c\u3070\u308c\u3001\u95a2\u6570\u578b\u8a00\u8a9e\u304b\u3089\u306e\u501f\u7528\u3067\u3042\u308b\u3002\u307b\u3093\u3068\u306f\u3053\u3053\u304b\u3089\u304c\u307e\u305f\u9762\u767d\u3044\u3093\u3060\u3051\u3069\u3001\u307e\u3042\u5f8c\u306f\u9069\u5f53\u306b\u8abf\u3079\u3066\u3084\u3063\u3066\u304f\u308c\uff57 \u3042\u308b\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u306b\u5225\u306e\u8a00\u8a9e\u306e\u30d1\u30e9\u30c0\u30a4\u30e0\u304c\u5c0e\u5165\u3055\u308c\u308b\u306e\u3063\u3066\u3001\u3059\u3054\u304f\u30b9\u30ea\u30ea\u30f3\u30b0\u3060\u3088\u306d\u3002\u308f\u304f\u308f\u304f\u3057\u3061\u3083\u3046\u3002\u500b\u4eba\u7684\u306b\u3001C#1.0 \u306e\u3068\u304d\u3088\u308a\u308f\u304f\u308f\u304f\u3057\u3066\u308b\u308f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

\u3068\u306b\u304b\u304f\u5e03\u6559\u3057\u305f\u3044\u6c17\u5206\u306a\u306e\u3067\u3002\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3068\u3044\u3046\u5bfe\u8c61\u306b\u5bfe\u3057\u3066\u3001\u7d14\u7c8b\u306b\u9762\u767d\u3044\u3068\u611f\u3058\u3066\u308b\u306e\u306f\u4e45\u3057\u3076\u308a\u306a\u306e\u3067\u3002 \u4f8b\u306e\u3054\u3068\u304f\u3001C#3.0\u3002\u305d\u306e\u697d\u3057\u3055\u3092\u55a7\u4f1d\u3057\u305f\u3044\u3060\u3051\u3067\u3042\u3063\u3066\u3001\u5165\u9580\u3068\u8a00\u3048\u308b\u3088\u3046\u306a\u6574\u7136\u3068\u3057\u305f\u3082\u306e\u3058\u3083\u3042\u306a\u3044\u306e\u3067\u3002 […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,11],"tags":[],"_links":{"self":[{"href":"https:\/\/blog.tksk.net\/index.php?rest_route=\/wp\/v2\/posts\/1190"}],"collection":[{"href":"https:\/\/blog.tksk.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.tksk.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.tksk.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.tksk.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1190"}],"version-history":[{"count":0,"href":"https:\/\/blog.tksk.net\/index.php?rest_route=\/wp\/v2\/posts\/1190\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.tksk.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1190"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.tksk.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1190"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.tksk.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1190"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}