如何检查字符串是否是JavaScript中的有效EAN / GTIN条形码？
我需要检查EAN8，EAN12，EAN13，EAN14，EAN18以及GTIN12，GTIN13，GTIN14。
答案 0 :(得分：22)
编辑我还创建了一个npm模块，可以在github找到。
我创建了一个小型库，支持EAN8，EAN12，EAN13，EAN14，EAN18，GTIN12，GTIN13和GTIN14。
它在node.js和所有现代浏览器中运行。
<强> barcoder.js：
/*!
* Barcoder
* Copyright (c) 2013 mifitto GmbH <dominik@mifitto.com>
* MIT Licensed
*/
(function() {
'use strict';
/**
* Library version.
*/
var version = '1.1.0';
/**
* Supported formats
*/
var minValidLength = 6;
var maxValidLength = 18;
var usualValidChars = /^\d+$/;
var formats = {
'ean8' : { validChars : /^\d+$/, validLength : 8 },
'ean12' : { validChars : /^\d+$/, validLength : 12 },
'ean13' : { validChars : /^\d+$/, validLength : 13 },
'ean14' : { validChars : /^\d+$/, validLength : 14 },
'ean18' : { validChars : /^\d+$/, validLength : 18 },
'gtin12' : { validChars : /^\d+$/, validLength : 12 },
'gtin13' : { validChars : /^\d+$/, validLength : 13 },
'gtin14' : { validChars : /^\d+$/, validLength : 14 }
};
/**
* Validates the checksum (Modulo 10)
* GTIN implementation factor 3
*
* @param {String} value The barcode to validate
* @return {Boolean}
* @api private
*/
var validateGtin = function( value ) {
var barcode = value.substring( 0, value.length - 1 );
var checksum = parseInt( value.substring( value.length - 1 ), 10 );
var calcSum = 0;
var calcChecksum = 0;
barcode.split('').map(function( number, index ) {
number = parseInt( number, 10 );
if ( value.length % 2 === 0 ) {
index += 1;
}
if ( index % 2 === 0 ) {
calcSum += number;
}
else {
calcSum += number * 3;
}
});
calcSum %= 10;
calcChecksum = (calcSum === 0) ? 0 : (10 - calcSum);
if ( calcChecksum !== checksum ) {
return false;
}
return true;
};
/**
* Barcoder class
*
* @param {string} format See formats
* @param {Object} options Valid option `enableZeroPadding`, defaults to `true`
* @api public
*/
var Barcoder = function ( format, options ) {
if ( format && !formats[format] ) throw new Error( '"format" invalid' );
this.format = (format) ? formats[format] : 'autoSelect';
this.options = (options) ? options : { enableZeroPadding : true };
if ( !this.options.enableZeroPadding ) {
this.options.enableZeroPadding = true;
}
};
/**
* Validates a barcode
*
* @param {string} barcode EAN/GTIN barcode
* @return {Boolean}
* @api public
*/
Barcoder.prototype.validate = function( barcode ) {
var self = this;
if ( self.format === 'autoSelect' ) {
if ( barcode.length < minValidLength || barcode.length > maxValidLength ) {
return false;
}
var isValidGtin = validateGtin( barcode );
var paddedBarcode = barcode;
var successfullyPadded = false;
if ( !isValidGtin ) {
var possiblyMissingZeros = maxValidLength - barcode.length;
while( possiblyMissingZeros-- ) {
paddedBarcode = '0' + paddedBarcode;
if ( validateGtin( paddedBarcode ) ) {
isValidGtin = true;
successfullyPadded = true;
break;
}
}
}
return {
possibleType: (barcode.length > 8) ? 'GTIN' + barcode.length : 'EAN8 / padded GTIN',
isValid: isValidGtin
};
}
var validChars = self.format.validChars;
var validLength = self.format.validLength;
var enableZeroPadding = self.options.enableZeroPadding;
if ( validChars.exec( barcode ) === null ) {
return false;
}
if ( enableZeroPadding && barcode.length < validLength ) {
var missingZeros = validLength - barcode.length;
while( missingZeros-- ) {
barcode = '0' + barcode;
}
}
else if ( !enableZeroPadding && barcode.length != validLength ) {
return false;
}
else if ( barcode.length > validLength ) {
return false;
}
return validateGtin( barcode );
};
/**
* Export
*/
if ( 'undefined' !== typeof module && module.exports ) {
module.exports = Barcoder;
exports.version = version;
}
if ( 'undefined' === typeof ender ) {
this['Barcoder'] = Barcoder;
}
if ( 'function' === typeof define && define.amd ) {
define('Barcoder', [], function () {
return Barcoder;
});
}
}).call( this );
<强>安装：
$ npm install barcoder
<强>用法：
var Barcoder = require('barcoder');
var ean1 = '0016T20054453';
var ean2 = '9330071314999';
var validator = new Barcoder('ean13');
console.log( '%s ean1 is valid: %s', ean1, validator.validate( ean1 ) );
console.log( '%s ean2 is valid: %s', ean1, validator.validate( ean2 ) );
// or /w automatic type selection
validator = new Barcoder();
var validation1 = validator.validate( ean1 );
var validation2 = validator.validate( ean2 );
console.log( '%s is valid: %s and has guessed type: %s', ean1, validation1.isValid, validation1.possibleType );
console.log( '%s is valid: %s and has guessed type: %s', ean2, validation2.isValid, validation2.possibleType );
答案 1 :(得分：14)
我不知道为什么，但@doms解决方案对我来说无法正常工作。此外，我希望计算新代码以及验证旧代码。我最终得到了这个，我已经验证了我的浏览器至少工作了：
function eanCheckDigit(s){
var result = 0;
for (counter = s.length-1; counter >=0; counter--){
result = result + parseInt(s.charAt(counter)) * (1+(2*(counter % 2)));
}
return (10 - (result % 10)) % 10;
}
答案 2 :(得分：4)
这是一个简短版本，可以检查EAN13校验位是否有效：
var checkSum = ean.split('').reduce(function(p,v,i) {
return i % 2 == 0 ? p + 1 * v : p + 3 * v;
}, 0);
if (checkSum % 10 != 0) {
alert('error');
}
答案 3 :(得分：1)
这是我的解决方案，使用规范检查不同长度的条形码以计算最后的校验位（参见注释）：
// ean/gtin validation for 8, 12, 13 & 14 digit barcodes
function codeOnBlur(barcode) {
var barcodeLengthArr = [8, 12, 13, 14];
var allowedChars = new RegExp(/\d{8,14}/); // >7 & <15
// put numbers in array and convert to type Int.
var barcodeArray = barcode.split('');
for( var i = 0; i < barcodeArray.length; i++) {
barcodeArray[i] = parseInt(barcodeArray[i], 10);
}
// get the last digit for checking later
var checkDigit = barcodeArray.slice(-1)[0];
// we'll need a to compare it to this:
var remainder = 0;
// check if input (barcode) is in the array and check against the regex.
if (($.inArray(barcode.length, barcodeLengthArr) > -1) && (allowedChars.test(barcode))) {
console.log("barcodeArray ", barcodeArray, " :: checkDigit ", checkDigit);
// Pop the last item from the barcode array, test if the length is
// odd or even (see note on calculating the check digit) and
// multiply each item in array based in position:
var total = 0;
barcodeArray.pop();
// odd length after pop
if (barcodeArray.length % 2 === 1) {
for (var i = barcodeArray.length - 1; i >= 0; i--) {
barcodeArray[i] = i % 2 === 0 ? barcodeArray[i] * 3 : barcodeArray[i] * 1;
total += barcodeArray[i];
}
// even length after pop
} else if (barcodeArray.length % 2 === 0) {
for (var i = barcodeArray.length - 1; i >= 0; i--) {
barcodeArray[i] = i % 2 === 0 ? barcodeArray[i] * 1 : barcodeArray[i] * 3;
total += barcodeArray[i];
}
} else {
// validation passed = false
}
// calculate the remainder of totalrounded up to nearest multiple of 10:
remainder = (Math.ceil((total + 1) / 10) * 10) - total;
console.log("loop total = ", total, ", remainder: ", remainder);
if ( remainder === checkDigit ) {
//validation passed = true;
return;
} else {
//validation passed = false;
}
} else {
//validation Passed = false;
}
}
我确定这些代码可以整理一些：）
手动检查＆＃34;完整性位＆＃34;或检查数字：
barcode: 13: 4 0 1 1 2 0 0 2 9 6 9 0 8
8: 5 0 8 1 8 9 0 7
multiplier: 3 1 3 1 3 1 3 1 3 1 3 1 check digit
使8位数代码向后工作：
0*1 + 9*3 + 8*1 + 1*3 + 8*1 + 0*3 + 5*1 = 73
Difference from 73 to 80 is 7 (the specification will have you round up to
the nearest power of 10).
7是校验位和80-73的余数。
答案 4 :(得分：0)
这是我想出来的：
/**
* Test a string for valid EAN5 EAN8 EAN13 EAN14 EAN18
* @see: https://www.activebarcode.com/codes/ean13.html
* @param {string} ean A string to be tested
* @return {boolean} true for a valid EAN
* @author Vitim.us <https://stackoverflow.com/a/65928239/938822>
*/
function isValidEAN(ean) {
function testChecksum(ean) {
const digits = ean.slice(0, -1);
const checkDigit = ean.slice(-1) | 0;
let sum = 0;
for (let i = digits.length - 1; i >= 0; i--) {
sum += (digits.charAt(i) * (1 + (2 * (i % 2)))) | 0;
}
sum = (10 - (sum % 10)) % 10;
return sum === checkDigit;
}
ean = String(ean);
const isValidLength = ean.length === 18 || ean.length === 14 || ean.length === 13 || ean.length === 8 || ean.length === 5;
return isValidLength && /^\d+$/.test(ean) && testChecksum(ean);
}答案 5 :(得分：0)
GS1 US 发布了 GTIN 的校验位计算算法。它使用填充来计算各种条形码，实际上比我在上面找到的其他方法要简单得多。
它适用于 GTIN 条码：GTIN-8、GTIN-12 (UPC)、GTIN-13 (EAN) 和 GTIN-14 (ITF-14)。
function isValidBarcode(value) {
// We only allow correct length barcodes
if (!value.match(/^(\d{8}|\d{12,14})$/)) {
return false;
}
const paddedValue = value.padStart(14, '0');
let result = 0;
for (let i = 0; i < paddedValue.length - 1; i += 1) {
result += parseInt(paddedValue.charAt(i), 10) * ((i % 2 === 0) ? 3 : 1);
}
return ((10 - (result % 10)) % 10) === parseInt(paddedValue.charAt(13), 10);
}
答案 6 :(得分：-1)
function isBarcode(barcode) {
if (typeof barcode === 'number') {
throw 'RuntimeError: Barcode MUST NOT be in number format'
} else if (barcode.length!==12) {
throw 'RuntimeError: String length is not 12'
};
var _= barcode.toString().split("")
var _1 = 0
var _2 = 0
var __
for ($=0;$<=10;++$) {
_1+=+_[$]
};for ($=10;$>=0;$-=2) {
_2+=+_[$]
};_2*=2
var _3 = _1+_2
__=+_3.toString().substring(1,2)
if (__>9) {
__=+_3.toString().substring(1,2)
} else if (__===0) {
__=10
};
__=10-__
if (__===+_[11]) {
return true
}
return false
};