1.‘+’运算符
<script type="text/javascript">
x=5+5;
document.write(x);
document.write("<br />");
x="5"+"5";
document.write(x);
document.write("<br />");
x=5+"5";
document.write(x);
document.write("<br />");
x="5"+5;
document.write(x);
document.write("<br />");
</script>
运算结果是:
10
55
55
55
规则是:
如果把数字与字符串相加,结果将成为字符串。
2.条件运算符
greeting=(visitor=="PRES")?"Dear President ":"Dear ";