Node.js Stream 可写. write()方法
原文:https://www . geesforgeks . org/node-js-stream-write-write-method/
write . write()方法是 Stream 模块的内置应用编程接口，用于将一些数据写入可写流。一旦数据被完全处理，就调用回调函数。
语法:
writable.write( chunk, encoding, callback)
参数:该方法接受三个参数，如上所述，如下所述:
- Chunk: is an optional data writing. The value of the block must be a string, buffer or Uint 8 array. For object mode, the block value can be any value other than null.
- Code: If the chunk is a string value, the code value is saved.
- Callback: is an optional callback function of the stream.
返回值:如果在此方法返回真之前发出‘排空’事件，则返回假。
以下示例说明了在 Node.js 中使用可写. write()方法:
例 1:
// Node.js program to demonstrate the
// writable.write() method
// Including stream module
const stream = require('stream');
// Creating a stream and creating
// a write function
const writable = new stream.Writable({
// Write function with its
// parameters
write: function(chunk, encoding, next) {
// Converting the chunk of
// data to string
console.log(chunk.toString());
next();
}
});
// Calling write method with
// all its parameter
writable.write("GfG", "utf8", () => {
console.log("CS-Portal!");
});
输出:
GfG
true
CS-Portal!
例 2:
// Node.js program to demonstrate the
// writable.write() method
// Including stream module
const stream = require('stream');
// Creating a stream and creating
// a write function
const writable = new stream.Writable({
// Write function with its
// parameters
write: function(chunk, encoding, next) {
// Converting the chunk of
// data to string
console.log(chunk.toString());
next();
}
});
// Calling write method with one
// parameter
writable.write('GeeksforGeeks');
输出:
GeeksforGeeks
true
参考:https://nodejs . org/API/stream . html # stream _ write _ chunk _ encoding _ callback
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