Buffer.alloc(size[, fill[, encoding]])


    分配 size 个字节的新 Buffer。 如果 fillundefined,则 Buffer 将以零填充。

    Allocates a new Buffer of size bytes. If fill is undefined, the Buffer will be zero-filled.

    import { Buffer } from 'node:buffer';
    
    const buf = Buffer.alloc(5);
    
    console.log(buf);
    // Prints: <Buffer 00 00 00 00 00>const { Buffer } = require('node:buffer');
    
    const buf = Buffer.alloc(5);
    
    console.log(buf);
    // Prints: <Buffer 00 00 00 00 00>

    If size is larger than buffer.constants.MAX_LENGTH or smaller than 0, ERR_INVALID_ARG_VALUE is thrown.

    If fill is specified, the allocated Buffer will be initialized by calling buf.fill(fill).

    import { Buffer } from 'node:buffer';
    
    const buf = Buffer.alloc(5, 'a');
    
    console.log(buf);
    // Prints: <Buffer 61 61 61 61 61>const { Buffer } = require('node:buffer');
    
    const buf = Buffer.alloc(5, 'a');
    
    console.log(buf);
    // Prints: <Buffer 61 61 61 61 61>

    If both fill and encoding are specified, the allocated Buffer will be initialized by calling buf.fill(fill, encoding).

    import { Buffer } from 'node:buffer';
    
    const buf = Buffer.alloc(11, 'aGVsbG8gd29ybGQ=', 'base64');
    
    console.log(buf);
    // Prints: <Buffer 68 65 6c 6c 6f 20 77 6f 72 6c 64>const { Buffer } = require('node:buffer');
    
    const buf = Buffer.alloc(11, 'aGVsbG8gd29ybGQ=', 'base64');
    
    console.log(buf);
    // Prints: <Buffer 68 65 6c 6c 6f 20 77 6f 72 6c 64>

    Calling Buffer.alloc() can be measurably slower than the alternative Buffer.allocUnsafe() but ensures that the newly created Buffer instance contents will never contain sensitive data from previous allocations, including data that might not have been allocated for Buffers.

    A TypeError will be thrown if size is not a number.