Arrays of Objects is a talk-through in which Pamela demonstrates how to store arrays of Objects.
She starts out with a program previously used in the Variables section, which defines a function to draw Winston (called, appropriately enough, drawWinston...), and then includes four separate calls to that function, each with a different x
and y
parameter. She then demonstrates how, instead, two arrays could be used to store the corresponding x
and y positions, and looped through.
She goes on to explain that there's an easier way though. A single array can be created, including within it multiple objects, each of which stores one set of x
and y
coordinates. By then looping through those objects, the same drawing can be created with just that one array:
var positions = [ {x: 99, y: 117}, {x: 294, y: 117}, {x: 101, y: 316}, {x: 294, y: 316} ]; for (var i = 0; i < positions.length; i++) { drawWinston(positions[i].x, positions[i].y); }
Finally, she demonstrates that the drawWinston function can actually be modified to expect an object as input, rather than requiring the individual x
and y
values:
var drawWinston = function(facePosition) { var faceX = facePosition.x; var faceY = facePosition.y; // which can then be called by: for (var i = 0; i < positions.length; i++) { drawWinston(positions[i]); }