This topic explains how to write functions which can be used for debugging JavaScript programs. It is more technical than the other topics in this section and introduces a number of advanced concepts. If you are not planning to do advance JavaScript programming, you may wish to omit this topic. This is the most common and useful form of array.
Associative arrays are very much like numerically indexed arrays.
They also have cells which can contain values. These statements create the array above. In JavaScript, numerically indexed arrays and associative arrays are distinct data types. If the first reference is associative, then the whole array will be associative as long as it exists, and you will not be able to reference its cells by number. If the first reference is numeric, then you can thereafter reference the cells of the array only by number.