This will be just a quick canvas examples post on a object pool module and a little additional code that will make use of such a module. An object pool is what I have come to call a collection of display objects that are a fixed set of such objects rather than something where they are being added and removed on the fly. So in other words an object pool is a fixed collection of objects that are to be used over and over again, rather than a collection of objects that created and destroyed as needed.

So these objects will often contain properties like x and y for the current position as well as width, and height as one might expected with just about any display object in a simple 2d canvas project. Depending on the nature of the canvas project they will often have additional properties like heading, pixels per second, max hit points, damage, and so forth. However the main point of this canvas example is just to show one way of how to go about creating a collection of these kinds of objects.

There is creating a collection of objects as just an empty array, and then have code that pushes new display objects into the collection, and then purge them out when some kind of condition happens that will result in that happening. However there is also creating an array of display objects once, and when doing so making the fixed pool of a certain set length. I can then have an active property of a display object that is used to set if the display object is currently being used or not.

So then an object pool is a way of creating a collection of objects where I am setting fixed amounts of display objects rather than just pushing them in and out out as needed. That way I know for sure I will never end up with some kind of run away situation in which objects keep getting added. More objects means more overhead to have everything running, and although many computers are fast, I still think it terms of less is more when having display objects in a project. So then in this post I will be going over an example that involves a fixed object pool. This will involve a module that can be used to create a pool object, and a bunch of additional pubic methods to work with that pool, and also some additional code that is used to demo that module.

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In javaScript there is a standard way for creating a method for an object that will return what the string value for an object should be. This standard way of defining what a string primitive is for an object is the to string method. In addition to the to string method there is also the value of method that is a way to set what the number primitive value for an object should be. The toString method will be used in a javaScript expression where an object value needs to be converted to a string when using the object with a string value and the addition operator for example. As you would guess the value of method is more or less the same thing, but the primitive value returned by that function should be a number values rather than that of a string.

So then the toString method along with the value of methods of an object are standard way to define logic that will create a string or number primitive value of an object. In addition to this there are also constructor functions, and other static methods that will create an object from a primitive value. It is then worth it to write at least a little about this topic, so lets get to it here.

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So there is adding two strings or numbers together with the addition operator in javaScript, but then there is adding two or more objects together including Arrays and how such an operation should be handled. In the array prototype object there is the array concat method that can be used to create a new array that is the concatenation of two or more arrays, or values by themselves actually. Simply put the Array.concat method is one way to go about adding two or more arrays together into a single array.

There are then also ways of going about doing the same thing, such as converting an array to a string and then back again using something like the array join, and then string split methods. There are also methods in popular utility libraries, such as the concat method in lodash and well as join and split methods. Another thing that comes to mind is what is really intended by adding two arrays together, typically that would be just creating a new array with the elements of one or more arrays, but in some cased one might want a sum of one or more arrays of numbers.

There are also a number of things to look out for when concatenating arrays together when it comes to the values in the arrays. For example when it comes to having to arrays of objects the resulting array will be a new array, but the objects in the arrays will still reference the same objects in memory. So lets look at some examples of array concatenation with the array concat method, as well as other ways to go about getting a similar effect.

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This post will be on a fixed shooter hybrid canvas example game, like that of centipede. The game is like a fixed shooter type game like that of space invaders or kaboom, however the player is able to move by two axis of movement rather than just one.Still the player can not just move anywhere the play display object must stay in an area at the bottom of the screen. So then the player is not truly fixed to one axis, but is fixed to an area. I do not aim to make a true clone of centipede, but I would like to just make a clean canvas example of something that is similar to that classic game.

If I get more time to come around and add some more features I am not really sure what more I can add to it that would be taking this kind of game into a new direction. I also have so many other canvas examples that also could use some more work. All i wanted to do with this example is just get the basic idea of this kind of game up and working though, and that is what this is.

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The javaScript string index of method was introduced to javaScript a real long time ago. It is one of these javaScript prototype methods that is very safe to use because it was around almost since the beginning as the method works even in versions of Internet explorer as old as version 3. So there is not really a need to depend on some kind of polyfill method, or a user space alternative like lodash index of method that might very well just reference this native method anyway.

The string index of method will give an index value of a character in a string from the right to left that is the beginning of another string that is given as the first argument. In the event that at least one instance of the given string is found it will return an index value, in the event that it is not it will return the number negative one.

So then this string index of method in the string prototype object will work just fine when it comes to using strings rather than regular expressions, and if I am just interested in the first instance of a substring in another string from left to right. However in some situations I might want to get all index values of a fixed string, or even a pattern of sorts. When it comes to this the index of method falls short. To get all index values it would be better to use the exec method of the regular expression class rather than string index of method.

In addition to the index of property method there are other string prototype methods of interest such as string match, and string replace. When it comes to getting the index value of strings that fit a non fixed static pattern the match method might be a better choice. In addition the replace method is a better choice if you want to replace all instances of a sub string. Still this is a post mainly on the index of method so lets look at a few simple examples of the string index method here, and also maybe touch based on some related topics without getting into to much detail as i would on my posts on those methods.

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