JavaScript - calculate crc32

In this short article, we would like to show how in a simple way calculate CRC32 sum using JavaScript.

Practical example:

// ONLINE-RUNNER:browser;

const CRC_TABLE = Array(256);

for (let i = 0; i < 256; ++i) {
    let code = i;
    for (let j = 0; j < 8; ++j) {
      	code = (code & 0x01 ? 0xEDB88320 ^ (code >>> 1) : (code >>> 1));
    }
    CRC_TABLE[i] = code;
}

const crc32 = text => {
    let crc = -1;
    for (let i = 0; i < text.length; ++i) {
      	const code = text.charCodeAt(i);
        crc = CRC_TABLE[(code ^ crc) & 0xFF] ^ (crc >>> 8);
    }
    return (-1 ^ crc) >>> 0;
};


// Usage example:

console.log(crc32('This is example text ...'));  // 3473739588

See also

1. TypeScript - calculate crc32