JS-計算身份證校驗碼（最後一位）
阿新 • • 發佈：2019-01-03
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<!DOCTYPE html> <html lang="en"> <head> <title>Document</title> <style> #msg{ color: red; } </style> </head> <body> 身份證號：<input id="id-card" type="text">（前17位）<br> （校驗位）最後一位為：<span id="msg"></span><span id="check-digit"></span><br> <button onclick="calculate()">計算</button><br> <script> "use strict"; // 前17位每項的係數 let coefficient = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2]; // 除11取餘的結果對應的校驗位（最後一位）的值 let checkDigitMap = ['1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2']; function calculate(){ var idCard = document.querySelector("#id-card"); var checkDigit = document.querySelector("#check-digit"); var msg = document.querySelector("#msg"); var sum = 0; checkDigit.innerHTML = msg.innerHTML = ""; if(idCard.value.length < 17){ msg.innerHTML = "至少輸入身份證前17位"; return } for (var i = 0; i < 17; i++) { sum += idCard.value[i] * coefficient[i]; } checkDigit.innerHTML = checkDigitMap[sum % 11]; } </script> </body> </html>