H5有哪些清空画布方法

function clearCanvas<span style="font-family: Verdana, Arial, 宋体;">()</span> 

{ 

    var c=document.getElementById("myCanvas"); 

    var cxt=c.getContext("2d"); 

    c.height=c.height; 

}

function clearCanvas() 

{ 

    var c=document.getElementById("myCanvas"); 

    var cxt=c.getContext("2d"); 

    cxt.clearRect(0,0,c.width,c.height); 

}

function clearCanvas() 

{ 

    var c=document.getElementById("myCanvas"); 

    var cxt=c.getContext("2d"); 

    cxt.fillStyle="#000000"; 

    cxt.beginPath(); 

    cxt.fillRect(0,0,c.width,c.height); 

    cxt.closePath(); 

}