{"id":612,"date":"2019-08-22T11:43:24","date_gmt":"2019-08-22T03:43:24","guid":{"rendered":"http:\/\/blog.xrhoujie.com\/?p=612"},"modified":"2019-11-22T11:52:03","modified_gmt":"2019-11-22T03:52:03","slug":"javascript-call%e7%90%86%e8%a7%a3","status":"publish","type":"post","link":"http:\/\/blog.xrhoujie.com\/?p=612","title":{"rendered":"javascript call\u7406\u89e3"},"content":{"rendered":"

\u5728js\u4e2d\u6bcf\u4e2a\u51fd\u6570\u90fd\u6709\u4e24\u4e2a\u65b9\u6cd5\uff1acall()<\/code>,apply()<\/code>\u3002\u8fd9\u4e24\u4e2a\u65b9\u6cd5\u7684\u4f5c\u7528\u5c31\u662f\u8bbe\u7f6e\u51fd\u6570\u4f53\u5185this<\/code>\u6307\u5411\u7684\u503c\u3002\u5982\u4e0b\u9762\u8fd9\u4e2a\u4f8b\u5b50\uff1a<\/p>\n

function<\/span> sum<\/span>(<\/span>n<\/span>,<\/span> m<\/span>){<\/span>\r\n    return<\/span> n <\/span>+<\/span> m<\/span>;<\/span>\r\n}<\/span>\r\n\r\nfunction<\/span> sum1<\/span>(n<\/span>,<\/span> m<\/span>){<\/span>\r\n    return<\/span> sum<\/span>.<\/span>call<\/span>(<\/span>this<\/span>,<\/span> n<\/span>,<\/span> m<\/span>);<\/span>\r\n}<\/span>\r\n\r\nconsole<\/span>.<\/span>log<\/span>(<\/span>sum1<\/span>(<\/span>1<\/span>,<\/span> 3<\/span>));<\/span>   \/\/\u7ed3\u679c\u662f4<\/span><\/code><\/pre>\n
call<\/code>\u4f20\u9012\u7684\u53c2\u6570\u7b2c\u4e00\u4e2a\u662f\u8fd0\u884c\u51fd\u6570\u6240\u5728\u7684\u4f5c\u7528\u57df\uff0c\u4e00\u822c\u60c5\u51b5\u6211\u4eec\u4f7f\u7528\u7684\u65f6\u5019\u662fthis<\/code>.\u5f53\u7136\u4e5f\u53ef\u4ee5\u76f4\u63a5\u6307\u5b9a\u4f5c\u7528\u57df\uff0c\u6bd4\u5982\uff1a<\/p>\n
        var<\/span> name <\/span>=<\/span> \"han\"<\/span>;<\/span>\r\n\r\n        var<\/span> p2 <\/span>=<\/span> {<\/span>\r\n            name<\/span>:<\/span> \"Anna\"<\/span>,<\/span>\r\n            age<\/span>:<\/span> 25<\/span>\r\n        };<\/span>\r\n\r\n        function<\/span> say<\/span>(){<\/span>\r\n            console<\/span>.<\/span>log<\/span>(<\/span>this<\/span>.<\/span>name<\/span>);<\/span>\r\n        }<\/span>\r\n\r\n        say<\/span>();<\/span>       \/\/han<\/span>\r\n\r\n        say<\/span>.<\/span>call<\/span>(<\/span>p2<\/span>);<\/span>    \/\/Anna<\/span><\/code><\/pre>\n
\u540e\u9762\u8ddf\u591a\u4e2a\u76f4\u63a5\u7684\u53c2\u6570\uff0c\u8fd9\u4e2a\u53c2\u6570\u4e5f\u5c31\u662f\u5f53\u524d\u4f7f\u7528\u51fd\u6570\u7684\u53c2\u6570\u4e2a\u6570\u6bd4\u5982sum()<\/code>\u6709\u51e0\u4e2a\u53c2\u6570\u5c31\u4f20\u9012\u51e0\u4e2a\u53c2\u6570\u3002\u8fd9\u4e2ahaoxin<\/code>\u7ed9\u7684\u94fe\u63a5\u8bf4\u660e\u4e86call<\/a>\u3002\u800capply()<\/code>\u53ea\u63a5\u53d7\u4e24\u4e2a\u53c2\u6570\uff0c\u4e00\u4e2a\u662f\u4f5c\u7528\u57df\uff0c\u4e00\u4e2a\u53c2\u6570\u7684\u6570\u7ec4(\u4e5f\u53ef\u4ee5\u662farguments\u5bf9\u8c61)\u3002<\/p>\n
\u5f53\u7136call()<\/code>\u7684\u771f\u6b63\u4f5c\u7528\u8fd8\u5f88\u5927\u3002\u5b83\u7684\u4f5c\u7528\u8fd8\u53ef\u4ee5\u53d1\u6325\u5728\u7ee7\u627f<\/code>\u4e0a\u9762,\u8fd9\u91cc\u6f14\u793a\u4e00\u79cd\u7ee7\u627f\u65b9\u5f0f\uff1a<\/p>\n
        function<\/span> P1<\/span>(<\/span>name<\/span>){<\/span>\r\n            this<\/span>.<\/span>name <\/span>=<\/span> name<\/span>;<\/span>\r\n            this<\/span>.<\/span>say <\/span>=<\/span> function<\/span>(){<\/span>\r\n                console<\/span>.<\/span>log<\/span>(<\/span>'my name is %s'<\/span>,<\/span> this<\/span>.<\/span>name<\/span>);<\/span>\r\n            };<\/span>\r\n        }<\/span>\r\n\r\n        function<\/span> P2<\/span>(<\/span>name<\/span>){<\/span>\r\n            P1<\/span>.<\/span>call<\/span>(<\/span>this<\/span>,<\/span> name<\/span>);<\/span>\r\n        }<\/span>\r\n\r\n        var<\/span> p <\/span>=<\/span> new<\/span> P2<\/span>(<\/span>\"Jim\"<\/span>);<\/span>\r\n\r\n        p<\/span>.<\/span>say<\/span>();<\/span>      \/\/\u8fd9\u91cc\u7684\u7ed3\u679c\u5c31\u662f\u2018my name is Jim\u2019<\/span><\/code><\/pre>\n
\u719f\u7ec3\u4f7f\u7528call()<\/code>\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u5f88\u591a\uff01<\/p>\n
 <\/p>\n
\u8fd8\u6709\u4e2a\u66f4\u6e05\u695a\u5730\u89e3\u91ca\uff1a<\/p>\n
function b(){ \u6709\u4e2a\u9505\uff0c\u8ddf\u8c03\u6599 }<\/p>\n
function a(){ \u4f1a\u7092\u83dc }<\/p>\n
b\u8bf4\uff1aa \u5e2e\u6211\u7092\u4e2a\u83dc a\u8bf4\uff1a\u597d\u7684\uff0c\u4f60\u5148\u628a\u4f60\u7684\u9505\u7ed9\u6211\uff0c\u518d\u7ed9\u6211\u4e00\u4e9b\u539f\u6599\uff0c<\/p>\n
a.call(b,\u539f\u65991\uff0c\u539f\u65992\uff0c\u2026);<\/p>\n
\/\/ function P2(name){ P1.call(this, name); }<\/p>\n
p2\u53ea\u6709\u505a\u83dc\u6280\u80fd\uff0c\u4f46\u662f\u6ca1\u6709\u9505\u8ddf\u539f\u6599\uff0c\u77e5\u9053p1\u6709\u9505\u8ddf\u539f\u6599\uff0c\u4e8e\u662f\u501f\u7740p1\u7684\u4e1c\u897f\u6765 \u5b8c\u6210\u7ed3\u679c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5728js\u4e2d\u6bcf\u4e2a\u51fd\u6570\u90fd\u6709\u4e24\u4e2a\u65b9\u6cd5\uff1acall(),apply()\u3002\u8fd9\u4e24\u4e2a\u65b9\u6cd5\u7684\u4f5c\u7528\u5c31\u662f\u8bbe\u7f6e\u51fd\u6570\u4f53\u5185this\u6307\u5411\u7684\u503c\u3002 […]<\/p>\n","protected":false},"author":1,"featured_media":180,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[10],"tags":[19],"_links":{"self":[{"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=\/wp\/v2\/posts\/612"}],"collection":[{"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=612"}],"version-history":[{"count":1,"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=\/wp\/v2\/posts\/612\/revisions"}],"predecessor-version":[{"id":613,"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=\/wp\/v2\/posts\/612\/revisions\/613"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=\/wp\/v2\/media\/180"}],"wp:attachment":[{"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=612"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=612"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.xrhoujie.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=612"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}