xxxxxxxxxx<html><head><meta charset="utf-8"><title>W3Cschool教程(w3cschool.cn)</title></head><body><script>var x;document.write("<p>仅显示17位: ");x=12345678901234567890;document.write(x + "</p>");document.write("<p>0.2 + 0.1 = ");x=0.2+0.1;document.write(x + "</p>");document.write("<p>可以通过乘以10或除以10来计算: ");x=(0.2*10+0.1*10)/10;document.write(x +"</p>");</script></body></html>