Let stringValue = (null, binaryData) Ĭonsole.log(stringValue) // "Hello World"Ĭonsole.log(encodedValue) // SGVsbG8gV29ybGQ= You can also encode binary data to Base64 encoded ASCII text in JavaScript using the btoa() function: let binaryData = new Uint8Array() You now know how to encode and decode Base64 in JavaScript. This function takes the encoded value and decodes it from Base64: let myString = "Welcome to freeCodeCamp!" Ĭonsole.log(decodedValue) // Welcome to freeCodeCamp! You can also decode the encodedValue back to its original form using the atob() function. For example, if you have a string stored in a variable, as seen below, you can first encode it to Base64: let myString = "Welcome to freeCodeCamp!" Ĭonsole.log(encodedValue) // V2VsY29tZSB0byBmcmVlQ29kZUNhbXAh ![]() You can encode a string to base64 in JavaScript using the btoa() function and decode a base64 string using atob() function. These JavaScript helper functions are named after old Unix commands for converting binary to ASCII (btoa) and ASCII to binary (atob). To encode and decode in JavaScript, you will use the btoa() and atob() JavaScript functions that are available and supported by modern web browsers. ![]() How to Encode and Decode HTML Base64 using JavaScript The resulting binary data is a reconstruction of the original binary data encoded to Base64. It takes a Base64 encoded string and maps each character back to its 6-bit binary representation. The result is a string of ASCII characters that can be transmitted or stored as text.īase64 decoding is the reverse process of encoding. ![]() The encoding process takes 3 bytes of binary data and maps it to 4 characters from the above set, such that a single character represents every 6 bits of binary data. The 64 characters used in Base64 encoding are: A-Z, a-z, 0-9, +, and /. It is commonly used to encode data that needs to be stored or transmitted in a way that cannot be directly represented as text.īase64 encoding works by mapping binary data to 64 characters from the ASCII character set. What is Base64?īase64 is a group of binary-to-text encoding schemes representing binary data in ASCII string format. In this article, you will learn about Base64 and how it works to convert binary data, regular strings, and lots more into ASCII text. This is possible thanks to two Base64 helper functions that are part of the HTML specification and are supported by all modern browsers. Just use with CROSS APPLY if doing a set-based operation.When building an application or writing a program, you may need to encode or decode with HTML Base64 in JavaScript. 'T8O5IGVzdCBsZSBjYWbDqSBsZSBwbHVzIHByb2NoZT8=') This method cannot be used to convert UTF-16 into UTF-8 or some other non-SQL Server-supported encoding.īelow is an Inline-TVF encapsulating the steps shown above: GOįROM dbo.ConvertBase64EncodedUTF8ToUTF16LE( Please note that this trick only works for converting from various source encodings into UTF-16 Little Endian (as that is how the XML datatype in SQL Server stores strings internally). ![]() In a DB with a Hebrew Collation, it gets the following error:Ĭonversion of one or more characters from XML to target collation impossible specified by the default Collation of the current Database:ĬONVERT(XML, '' + In a DB with a Latin1_General Collation it works: This is to VARCHAR, but "success" will depend on the Code Page This is to NVARCHAR, which will always work:ĬONVERT(XML, '' + Où est le café le plus proche? The trick to this trick is that you need to add the declaration (typically omitted) and specify the source encoding: DECLARE NVARCHAR(500) = N'T8O5IGVzdCBsZSBjYWbDqSBsZSBwbHVzIHByb2NoZT8=' ĬONVERT(XML, VARCHAR(500) = CONVERT(VARCHAR(500), 0x4FC3B920657374206C6520636166C3A9206C6520706C75732070726F6368653F The trick is to convert the Base64 decoded bytes, in their text representation (even with incorrectly converted characters) into XML. Hence, ù is the 8-bit version of the two-byte UTF-8 sequence for ù ( 0xC3 and 0xB9).įortunately, it is possible to convert a UTF-8 encoded string into UTF-16, or even into a non-Unicode Code Page (IF the Code Page supports all characters being converted). SQL Server uses UTF-16 Little Endian only for NVARCHAR data, and even for XML. So, decoding the Base64 gives you back the original UTF-8 sequence of bytes. The problem is that you encoded a UTF-8 encoded string into Base64.
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