JAVASCRIPT

javascript relational operators

var point = { x:1, y:1 };        // Define an object
var has_x_coord = "x" in point;  // Evaluates to true
var has_y_coord = "y" in point;  // Evaluates to true
var has_z_coord = "z" in point;  // Evaluates to false; not a 3-D point
var ts = "toString" in point;    // Inherited property; evaluates to true