Node.js Stream 可写可写属性
原文:https://www . geesforgeks . org/node-js-stream-written-written-property/
可写可写属性是 Stream 模块的内置应用编程接口，用于检查可写. write()方法调用是否安全。
语法:
writable.writable
返回值:如果可以安全调用 writable.write()方法，则返回 true，否则返回 false。
下面的例子说明了可写属性在 Node.js 中的使用:
例 1:
// Node.js program to demonstrate the
// writable.writable Property
// Accessing 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();
}
});
// Writing data
writable.write('hi');
// Again writing some data
writable.write('GFG');
// Calling writable.writable
// Property
writable.writable;
输出:
hi
GFG
true
例 2:
// Node.js program to demonstrate the
// writable.writable Property
// Accessing 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();
}
});
// Writing data
writable.write('hi');
// Again writing some data
writable.write('GFG');
// Calling end() method
writable.end();
// Calling writable.writable
// Property
writable.writable;
输出:
hi
GFG
false
在上面的示例中，输出为 false，因为在调用 writable.write 属性之前调用了 writable.end()方法，所以调用 writable.write()方法是不安全的，因此输出为 false。
参考:T2】https://nodejs.org/api/stream.html#stream_writable_writable
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