This looks at the cost of assigning a new

Remove item from array with indexOf, splice, filter and copy

Fill Array(1000) with random 1 - 999999 inclusive

JavaScript spread operator vs Object.assign performance, fixed. The original test did not create new object for the Object.assign case

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

Testing isArray vs jQuery.type === "array"

Object lookup performance

Compare loop performance