我有两个列表，其中包含相同的对象。
List<Object1> list1;
List<Object1> list2;
for (Object1 objectItem : list1.getList()) {
// I want to check if objectItem exists in list2 without using another for loop and then compare their other values
// Something like list2.getList().contains(objectItem).getThisValueMethod();
}
这可能吗？
答案 0 :(得分：2)
考虑这个示例（import UIKit
import SpriteKit
import PlaygroundSupport
let radius = CGFloat(100)
let sceneSize = CGSize(width: 640, height: 480)
let sceneView = SKView(frame: CGRect(origin: CGPoint.zero, size: sceneSize))
let scene = SKScene(size: sceneSize)
scene.backgroundColor = UIColor.black
let topRightPath = arcSegment(radius: radius, strokeWidth: 18, gapWidth: 25)
let topRightPathNode = SKShapeNode(path: topRightPath)
topRightPathNode.fillColor = SKColor.white
topRightPathNode.position = CGPoint(x: 320, y: 240)
topRightPathNode.lineWidth = 0
scene.addChild(topRightPathNode)
var reflectOnY = CGAffineTransform(scaleX: 1.0, y: -1.0)
let bottomRightPath = topRightPath.copy(using: &reflectOnY)!
let bottomRightPathNode = SKShapeNode(path: bottomRightPath)
bottomRightPathNode.fillColor = SKColor.orange
bottomRightPathNode.position = CGPoint(x: 320, y: 240)
bottomRightPathNode.lineWidth = 0
scene.addChild(bottomRightPathNode)
var reflectOnX = CGAffineTransform(scaleX: -1.0, y: 1.0)
let bottomLeftPath = bottomRightPath.copy(using: &reflectOnX)!
let bottomLeftPathNode = SKShapeNode(path: bottomLeftPath)
bottomLeftPathNode.fillColor = SKColor.green
bottomLeftPathNode.position = CGPoint(x: 320, y: 240)
bottomLeftPathNode.lineWidth = 0
scene.addChild(bottomLeftPathNode)
let topLeftPath = bottomLeftPath.copy(using: &reflectOnY)!
let topLeftPathNode = SKShapeNode(path: topLeftPath)
topLeftPathNode.fillColor = SKColor.blue
topLeftPathNode.position = CGPoint(x: 320, y:240)
topLeftPathNode.lineWidth = 0
scene.addChild(topLeftPathNode)
sceneView.presentScene(scene)
PlaygroundPage.current.liveView = sceneView
PlaygroundPage.current.needsIndefiniteExecution = true
func arcSegment( radius: CGFloat,
strokeWidth: CGFloat,
gapWidth: CGFloat) -> CGPath
{
let halfStrokeWidth = strokeWidth / 2.0
let outerRadius = radius + halfStrokeWidth
let innerRadius = radius - halfStrokeWidth
let halfGap = gapWidth / 2.0
let outerStartAngle = CGFloat(atan2(sqrt(outerRadius * outerRadius - halfGap * halfGap), halfGap))
let outerEndAngle = CGFloat(atan2(halfGap, sqrt(outerRadius * outerRadius - halfGap * halfGap)))
let innerStartAngle = CGFloat(atan2(halfGap, sqrt(innerRadius * innerRadius - halfGap * halfGap)))
let innerEndAngle = CGFloat(atan2(sqrt(innerRadius * innerRadius - halfGap * halfGap), halfGap))
let leftEndAngle = CGFloat(atan2(sqrt(radius * radius - halfGap * halfGap), halfGap))
let leftEndCapPoint = CGPoint(x: radius * cos(leftEndAngle),
y: radius * sin(leftEndAngle))
let rightEndCapPoint = CGPoint(x: leftEndCapPoint.y,
y: leftEndCapPoint.x)
let path = CGMutablePath()
path.addArc(center: CGPoint.zero,
radius: outerRadius,
startAngle: outerStartAngle,
endAngle: outerEndAngle,
clockwise: true)
path.addArc(center: rightEndCapPoint,
radius: halfStrokeWidth,
startAngle : 0,
endAngle : CGFloat.pi,
clockwise: true)
path.addArc(center: CGPoint.zero, radius: innerRadius, startAngle: innerStartAngle, endAngle: innerEndAngle, clockwise: false)
path.addArc(center: leftEndCapPoint,
radius: halfStrokeWidth,
startAngle : 3.0 * CGFloat.pi / 2.0,
endAngle : CGFloat.pi / 2.0,
clockwise: true)
path.closeSubpath()
return path
}
）：
Explanation in Comments