为什么TypeScript对我这样做没有问题：
return {
Price: value.rawPrice === null ? null : value.rawPrice
}
但我这样做有问题：
return {
Price: null
}
字段Price的类型编号为
答案 0 :(得分：0)
这是因为编译器中的var balls = [];
var obstacle;
function setup() {
createCanvas(windowWidth, windowHeight);
obstacle = new Obstacle();
}
function draw() {
background(75);
obstacle.display();
for(var i = 0; i < balls.length; i++) {
balls[i].display();
balls[i].update();
balls[i].edges();
console.log(RectCircleColliding(balls[i], obstacle));
}
}
function mousePressed() {
balls.push(new Ball(mouseX, mouseY));
}
function Ball(x, y) {
this.x = x;
this.y = y;
this.r = 15;
this.gravity = 0.5;
this.velocity = 0;
this.display = function() {
fill(255, 0 , 100);
stroke(255);
ellipse(this.x, this.y, this.r*2);
}
this.update = function() {
this.velocity += this.gravity;
this.y += this.velocity;
}
this.edges = function() {
if (this.y >= windowHeight - this.r*2) {
this.y = windowHeight - this.r*2;
this.velocity = this.velocity* -1;
this.gravity = this.gravity * 1.1;
}
}
}
function Obstacle() {
this.x = windowWidth - windowWidth;
this.y = windowHeight / 2;
this.w = 200;
this.h = 25;
this.display = function() {
fill(0);
stroke(255);
rect(this.x, this.y, this.w, this.h);
}
}
function RectCircleColliding(Ball, Obstacle) {
// define obstacle borders
var bRight = Obstacle.x + Obstacle.w;
var bLeft = Obstacle.x;
var bTop = Obstacle.y;
var bBottom = Obstacle.y + Obstacle.h;
//compare ball's position (acounting for radius) with the obstacle's border
if(Ball.x + Ball.r > bLeft)
if(Ball.x - Ball.r < bRight)
if(Ball.y + Ball.r > bTop)
if(Ball.y - Ball.r < bBottom)
return(true);
return false;
}
。
答案 1 :(得分：-1)
使用 undefined 代替 null