1.1
if (...)
{
...
}
else
{
...
}
<!DOCTYPE html> <html> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <body> <script charset = "utf-8"> function myfunction(){ var x = 11; var y = x % 2; document.write(y + "<br>"); if (x % 2 == 1){ document.write("单数"); } else { document.write("双数"); } } myfunction(); </script> </body> </html>
1.2
if (条件1)
{
...
}
else if (条件2)
{
...
}
else
{
...
}
<!DOCTYPE html> <html> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <body> <script charset = "utf-8"> function myfunction(x){ var y = x % 2; if (x % 2 == 0){ document.write("双数"); } else if (x > 10) { document.write("大于10的单数"); } else { document.write("普通单数"); } document.write("<br>"); document.write(x); } myfunction(15); </script> </body> </html>
原文：https://www.cnblogs.com/zrmw/p/10329903.html