canvas -矩形

const createRect = w=>{
    switch (w){
        case("rect"):
            return _=>{
                ctx.lineWidth = 10;
                ctx.strokeStyle = "#EEF2F0";
                ctx.shadowColor = "#78B359";
                ctx.shadowOffsetX = 5;
                ctx.shadowOffsetY = 5;
                ctx.rect(10,10,100,100);
                ctx.stroke();
            };
        case("fillRect"):
            return _=>{
                ctx.fillRect(100,100,300,300);
            };
        case("strokeRect"):
            return _=>{
                ctx.strokeRect(100,100,300,300);
            };
        case("clearRect"):
            return _=>{
                ctx.clearRect(100,100,300,300);
            }
    }
};

var rect1 = createRect("rect");
rect1();
var rect2 = createRect("fillRect");
rect2();
var rect3 = createRect("strokeRect");
rect3();
var rect4  = createRect("clearRect");
rect4();