$a = "張先生";

$tip1 = $a.",歡迎您在慕課網(wǎng)學習PHP！";

? ??

$a .= ",歡迎您在慕課網(wǎng)學習PHP！";

? ??

? ? $b = "東邊日出西邊雨";

? ? $b .= ",道是無晴卻有晴";

? ??

$c = "東邊日出西邊雨";

? ? $d = $c.",道是無晴卻有晴";

? ??

echo ?$tip1."<br /><br />";

? ? echo ?$a."<br /><br />";

echo ?$b."<br /><br />";

echo ?$d."<br /><br />";