index.md

layout	default
title	Node Cheat Sheet

Buffers

Class: Buffer

Buffer.from(array)
Buffer.from(arrayBuffer[, byteOffset[, length]])
Buffer.from(buffer)
Buffer.from(object[, offsetOrEncoding[, length]])
Buffer.from(string[, encoding])
Buffer.alloc(size[, fill[, encoding]])
Buffer.allocUnsafe(size)
Buffer.allocUnsafeSlow(size)

Instance: buf

buf.slice([start[, end]])
buf.compare(target[, targetStart[, targetEnd[, sourceStart[, sourceEnd]]]])
buf.copy(target[, targetStart[, sourceStart[, sourceEnd]]])
buf.entries()
buf.equals(otherBuffer)
buf.fill(value[, offset[, end]][, encoding])
buf.includes(value[, byteOffset][, encoding])
buf.indexOf(value[, byteOffset][, encoding])
buf.keys()
buf.lastIndexOf(value[, byteOffset][, encoding])
buf.length
buf.toString([encoding[, start[, end]]])
buf.values()
buf.write(string[, offset[, length]][, encoding])

## [Control Flow](#control-flow)

### Callback pattern

function foo(val1, val2, callback) { ... callback(); }

### Promise pattern

function foo(ok) { return new Promise(resolve, reject) { if (ok) { resolve('success'); } else { reject('boo'); } } }

foo() .then(res => { console.log(res); }) .catch(err => { throw err; })

### Async/Await

async function callFoo() { try { const result = await foo(true); } catch(err) { throw err; } }

## [Events](#events)

Class: events.EventEmitter

emitter.addListener(event, listener) emitter.on(event, listener) emitter.once(event, listener) emitter.removeListener(event, listener) emitter.removeAllListeners([event]) emitter.setMaxListeners(n) emitter.listeners(event) emitter.emit(event, [arg1], [arg2], [...]) Event: 'newListener'

## [Child Processes](#child-process)

Class: child_process

const child_process = require('child_process')

child_process.exec(command[, options][, callback]) child_process.execFile(file[, args][, options][, callback]) child_process.fork(modulePath[, args][, options]) child_process.spawn(command[, args][, options])

subprocess.send(message[, sendHandle[, options]][, callback])