This is how that code can be translated to JavaScript. Note that there is a typo in your code, and in that of the article, as the comments have suggested. Specifically r2->right left
should be r2->right < r1->left
and r2->bottom top
should be r2->bottom < r1->top
for the function to work.
function intersectRect(r1, r2) {
return !(r2.left > r1.right ||
r2.right < r1.left ||
r2.top > r1.bottom ||
r2.bottom < r1.top);
}
Test case:
var rectA = {
left: 10,
top: 10,
right: 30,
bottom: 30
};
var rectB = {
left: 20,
top: 20,
right: 50,
bottom: 50
};
var rectC = {
left: 70,
top: 70,
right: 90,
bottom: 90
};
intersectRect(rectA, rectB); // returns true
intersectRect(rectA, rectC); // returns false