Java Script BASICS

The command: ellipse( 200,100, 20, 20) will draw:

• an ellipse that is 100 pixels wide and 100 pixels high
• a circle whose center is 200 pixels across and 100 pixels down
• a rectangle that is 200 pixels by 100 pixels wide
• a circle that is 200 pixels in diameter

After running the following code, what will be the value of x?
y = 3;
x = 5 * y;

• 3
• 5
• 15
• 0

A variable is used to:

• Store a value in memory
• Draw a circle
• Store a value that does not change
• Draw a rectangle

The following code section will:
x = 0;
draw = function() {
rectangle(x, 50, 50, 25);
x++;
}

• Draw lots of ellipses across the screen
• Draw lots of rectangles across the screen
• Draw a rectangle
• Draw an ellipse

Any code that is within the following draw function:
draw = function(){
......
}

• Will be performed twice
• Will not be performed
• Will be performed once
• Will be repeated over and over again

The following code will:
x++;

• Add 1 to the previous value of x
• Add 1 to the previous value of y
• Subtract 1 from the previous value of x
• Give an error message

The following code will:
var xPos = 15;
var yPos = 350;
var xwidth = 50;
var ywidth = 50;
draw = function() {   
     background(29, 40, 115);   
     fill(255, 242, 0);   
     ellipse(xPos, yPos, xwidth, ywidth);              xPos++;   
     yPos--;   
     xwidth = xwidth* 99/100;   
     ywidth = ywidth * 99/100;
};

• Draw a circle that moves right to left accross the screen, getting smaller
• Draw a circle that moves diagonally accross the screen, getting bigger
• Draw a circle that moves diagonally accross the screen, getting smaller
• Draw a circle that moves right to left accross the screen, getting bigger

The code:
draw = function() {
ellipse(mouseX, mouseY, 30, 30);
}
will:

• Draw a circle
• Draw many circles according to the mouse position
• Draw an oval
• Draw many circles in the center of the screen

The output of the following code will be:
fill(0, 13, 255);
textSize(38);
text("Sophia", 99, 96);

• Sophia in colour blue
• "Sophia" in white
• The number 38
• A rectangle

The following code will:
fill(255, 0, 255);
draw = function() {   
background(255, 255, 255);   
ellipse(mouseX, mouseY, 12, 12);   
var label = mouseX + "," + mouseY;    text(label,mouseX,mouseY);
};

• Draw a circle that follows the mouse
• Draws a circle that follows the mouse and displays the mouse coordinates
• Draws a circle at x =255 and y = 255
• Draws an oval