SOURCE

console 命令行工具 X clear

                    
>
console
function setup(){
    createCanvas(500,500);
    background(255);
}
function draw(){
    for(let x=0; x<500; x+=50){
        for(let y=0; y<500; y+=50){
        	rect(x,y,25,25);
            for(let x=25; x<500; x+=50){
               for(let y=25; y<500; y+=50){ 
                   rect(x,y,25,25);
                   fill(0)
               }
            }
        }
    }
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.1.9/p5.min.js"></script>