doc: remove extra spaces and concats in examples

PR-URL: https://github.com/nodejs/node/pull/7885
Reviewed-By: Brian White <mscdex@mscdex.net>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Michaël Zasso <mic.besace@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/addons.md

@@ -423,7 +423,7 @@ const addon = require('./build/Release/addon');
 
 var obj1 = addon('hello');
 var obj2 = addon('world');
-console.log(obj1.msg + ' ' + obj2.msg); // 'hello world'
+console.log(obj1.msg, obj2.msg); // 'hello world'
 ```
 
 

doc/api/child_process.md

@@ -814,7 +814,7 @@ const spawn = require('child_process').spawn;
 
 let child = spawn('sh', ['-c',
   `node -e "setInterval(() => {
-      console.log(process.pid + 'is alive')
+      console.log(process.pid, 'is alive')
     }, 500);"`
   ], {
     stdio: ['inherit', 'inherit', 'inherit']

doc/api/process.md

@@ -171,7 +171,7 @@ Here is an example that logs every unhandled rejection to the console
 
 ```js
 process.on('unhandledRejection', (reason, p) => {
-    console.log("Unhandled Rejection at: Promise ", p, " reason: ", reason);
+  console.log('Unhandled Rejection at: Promise', p, 'reason:', reason);
   // application specific logging, throwing an error, or other logic here
 });
 ```