For in vs object keys test

For in vs object keys

Test TextEncoder encoding vs simply encoding with a string

Compare the new ES6 spread operator with the traditional concat() method and push

Compares different approaches to set an object property

iterating over an array to test whether every element satisfies a condition the for loop uses "inlining" (the condition is right there, without an extra function call) the call to every uses the predefined lambda ("cond")

Compare the new ES6 spread operator with the traditional concat() method and push