Some inquiries about using JavaScript arrays and their built-in functions

Question

Some inquiries about using JavaScript arrays and their built-in functions

![enter image description here][1]

function setFood () {
   var empty = [];
   for (var x=0; x<grid.width; x++) {
      for (var y=0; y>grid.height; y++) {

          if (grid.get(x,y) === EMPTY) {
          empty.push({x:x, y:y}); 
      }
    }
  }
};

While watching a tutorial on YouTube about creating a snake game, I stumbled upon this code snippet while the developer was writing a function.

This has sparked my curiosity and I have several questions that I am eager to find answers to in order to deepen my learning.

First of all, what does the .get method do? My search results mentioned jQuery, but there was no reference to using the jQuery library. What impact does it have on plain JavaScript code? Also, what is the significance of EMPTY? Is it a predefined term in JavaScript equivalent to 0 or `null`? Lastly, why is the creator using brackets within the push method? What exactly does it add to the empty array? And what do x:x and y:y signify?

I apologize for bombarding with questions, but I lack direct access to people who can help me with coding queries apart from the coding community itself.

javascript

Answer 1

Answer №1

empty is actually an array, defined with var empty = [];. However, it's important to note that EMPTY is a separate variable in JavaScript. The language is case-sensitive, so EMPTY is not synonymous with the empty[] array. It is typical practice to use all uppercase letters for constants to clearly distinguish them from other variables. In this context, EMPTY is a variable that represents an empty cell value.

When we execute empty.push({x:x, y:y});, we are adding a JavaScript object {x:x, y:y} to the array. The curly braces indicate the object syntax in JavaScript and contain properties for x and y, which are obtained using the get() method of the grid.

The grid mentioned here is likely an object declared elsewhere in the codebase. Without access to the complete code, my assumption is that grid stores information about the grid where the snake is moving, and get() is a function for retrieving the status of a specific element within that grid.

Answer 2

empty is actually an array, defined with var empty = [];. However, it's important to note that EMPTY is a separate variable in JavaScript. The language is case-sensitive, so EMPTY is not synonymous with the empty[] array. It is typical practice to use all uppercase letters for constants to clearly distinguish them from other variables. In this context, EMPTY is a variable that represents an empty cell value.

When we execute empty.push({x:x, y:y});, we are adding a JavaScript object {x:x, y:y} to the array. The curly braces indicate the object syntax in JavaScript and contain properties for x and y, which are obtained using the get() method of the grid.

The grid mentioned here is likely an object declared elsewhere in the codebase. Without access to the complete code, my assumption is that grid stores information about the grid where the snake is moving, and get() is a function for retrieving the status of a specific element within that grid.

Answer 3

Answer №2

Query 1:

I am unable to locate the source of the .get() function within the provided code snippet. It does not seem to be a part of the Array prototype.

Query 2:

In JavaScript, there is no reserved keyword as EMPTY, so it is likely serving as a reference to an empty variable (similar to jQuery's noop). Its definition might be similar to this:

var EMPTY = '';

Query 3:

The use of {} signifies an object in JavaScript. When combined with push(), it allows for pushing an object containing values of x and y into the empty array.

Answer 4

Query 1:

I am unable to locate the source of the .get() function within the provided code snippet. It does not seem to be a part of the Array prototype.

Query 2:

In JavaScript, there is no reserved keyword as EMPTY, so it is likely serving as a reference to an empty variable (similar to jQuery's noop). Its definition might be similar to this:

var EMPTY = '';

Query 3:

The use of {} signifies an object in JavaScript. When combined with push(), it allows for pushing an object containing values of x and y into the empty array.

Answer 5

Answer №3

To start, a grid is essentially an entity with attributes such as height and width, along with methods like get. For instance, consider the following template:

var grid = {
    height: 100,
    width: 200,
    get: function(p, q){
        return xyz;
    }
}

When it comes to EMPTY, it should be treated as a variable.

var EMPTY = null; //can also be 0 or '

'

We have the ability to instantiate an object as shown below:

var obj = {x:2, y:3};

The notation {x:x, y:y} denotes an object in which x and y represent their respective current values.

Answer 6

To start, a grid is essentially an entity with attributes such as height and width, along with methods like get. For instance, consider the following template:

var grid = {
    height: 100,
    width: 200,
    get: function(p, q){
        return xyz;
    }
}

When it comes to EMPTY, it should be treated as a variable.

var EMPTY = null; //can also be 0 or '

'

We have the ability to instantiate an object as shown below:

var obj = {x:2, y:3};

The notation {x:x, y:y} denotes an object in which x and y represent their respective current values.

Some inquiries about using JavaScript arrays and their built-in functions

Answer №1

Answer №2

Answer №3

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