{"resolved":true,"match_type":"uuid","source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","requested_by":"printed_page","book":{"source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","id":"38270854-596f-4a26-8183-db8c968c6020","uuid":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","normalized_title":"编码隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","isbns":["9787121181184","0123456789","6044921875","3039331000","0000000000","0000000000000"],"parsed":true,"ai_readable":true,"document_type":"book","page_count":438,"navigation_url":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020","title_url":"https://workshop.closeclaw.top/ai/title/%E7%BC%96%E7%A0%81%20%E9%9A%90%E5%8C%BF%E5%9C%A8%E8%AE%A1%E7%AE%97%E6%9C%BA%E8%BD%AF%E7%A1%AC%E4%BB%B6%E8%83%8C%E5%90%8E%E7%9A%84%E8%AF%AD%E8%A8%80","fixed_page_url_template":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","path_api_url_template":"https://workshop.closeclaw.top/api/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","read_url":"https://workshop.closeclaw.top/api/ai/read/38270854-596f-4a26-8183-db8c968c6020","page_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/page","search_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/search"},"page":{"printed_page":193,"pdf_page":209,"physical_index":209,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"fd770fcf17da9855b8a318b4d08e7b99103b2ac0d9dad31d6ac9489e49b8fd3c"},"chapter":"编码隐匿在计算机软硬件背后的语言","content":"十六进制数9A48Ch可以表示为如下形式：\n\n$$\n{ \\begin{array} { r l } { 9 . \\mathbf { A } 4 8 \\mathbf { C } \\mathbf { h } = 9 \\times 1 0 0 0 \\mathbf { h } + } & { } \\\\ { \\mathbf { A } \\times 1 0 0 0 \\mathbf { h } + } & { } \\\\ { 4 \\times 1 0 0 \\mathbf { h } + } & { } \\\\ { 8 \\times 1 0 \\mathbf { h } + } & { } \\\\ { \\mathbf { C } \\times 1 \\mathbf { h } } & { } \\end{array} }\n$$\n\n这个数用16的乘方表示可以写为：\n\n$$\n\\begin{array} { r } { 9 \\mathrm { A } 4 8 \\mathrm { C h } = 9 \\times 1 6 ^ { 4 } + } \\\\ { \\mathrm { A } \\times 1 6 ^ { 3 } + } \\\\ { 4 \\times 1 6 ^ { 2 } + } \\\\ { 8 \\times 1 6 ^ { \\dagger } + } \\\\ { \\mathrm { C } \\times 1 6 ^ { 0 } } \\end{array}\n$$\n\n也可以将16的幂进一步展开，写为如下形式：\n\n$$\n{ \\begin{array} { r c l } { 9 { \\mathrm { A } } 4 8 { \\mathrm { C h } } = 9 \\times 6 5 , 5 3 6 } \\\\ & { } \\\\ { \\qquad \\mathrm { A } \\times 4 0 9 6 \\ + } \\\\ & { } \\\\ { 4 \\times 2 5 6 \\ + } \\\\ & { } \\\\ { 8 \\times 1 6 \\ + } \\\\ & { } \\\\ { \\qquad \\subset \\times 1 } \\end{array} }\n$$\n\n我们可以仔细想想，如果只把一个数字（比如9，A，4，8和C中的任何一个）单独列举出来，而且不使用任何下标来指明其进制数，这种做法并不会产生二义性。无论在十进制还是十六进制下，一个单独的9仅代表9；而A的出现也说明了它本身是一个十六进制数—等价于十进制中的10。\n\n我们可以拿起笔和纸进行演算了，把十六进制数转换成十进制数：\n\n$$\n\\begin{array} { c } { 9 \\mathrm { A } 4 8 \\mathrm { C h } = 9 \\times 6 5 , 5 3 6 \\ + } \\\\ { 1 0 \\times 4 0 9 6 \\ + } \\\\ { 4 \\times 2 5 6 \\ + } \\\\ { 8 \\times 1 6 \\ + } \\\\ { 1 2 \\times 1 } \\end{array}\n$$\n\n运算的最后结果是631,948。这就是一个十六进制数转换成为十进制数的完整过程。\n\n下面给出了一种模板，它可以帮助我们把4位十六进制转换成为十进制。\n\n15 字节与十六进制\n\n193","previous_page":192,"next_page":194}