The code is too simple, so I won’t talk nonsense
var canvas=document.getElementById("canvas ");
//Set the drawing environment
var cxt=canvas.getContext('2d');
//Open a new path
cxt.beginPath();
// Set The width of the stroke
cxt.lineWidth=10;
//Set the color of the stroke
cxt.strokeStyle="#00ff00";
//Set the position of the stroke
cxt.moveTo( 20,20);
//Set the moving position
cxt.lineTo(100,20);
//Draw a line
cxt.stroke();//The line at this time has come out
//Close the path
cxt.closePath();
//All path graphics must start the path first, and the path must end after drawing