PHP learning log (3)-echo&print

      在php中，结果输出一共有两种方式：echo和print，下面将对两种方式做一个比较。

echo与print的区别：

	echo	print
连续输出字符串	能连续输出多个字符串	只能输出一个字符串
返回值	无	返回1
用法	echo或echo()	print或print()

（1）echo能连续输出多个字符串，print只能输出一个字符串：

实例1：

<span style="color: #000000">php
</span><span style="color: #008000">/*</span><span style="color: #008000">echo能连续输出多个字符串，print只能输出一个字符串</span><span style="color: #008000">*/</span>
<span style="color: #0000ff">echo</span> "echo输出一个字符串:"<span style="color: #000000">;
</span><span style="color: #0000ff">echo</span> "hello,world";  <span style="color: #008000">//</span><span style="color: #008000">echo输出一个字符串</span>
<span style="color: #0000ff">echo</span> "<br>"<span style="color: #000000">;
</span><span style="color: #0000ff">echo</span> "echo输出多个字符串:"<span style="color: #000000">;
</span><span style="color: #0000ff">echo</span> "hello,world","hello,php","hello,python";   <span style="color: #008000">//</span><span style="color: #008000">echo输出多个字符串</span>
<span style="color: #0000ff">echo</span> "<br>"<span style="color: #000000">;

</span><span style="color: #0000ff">print</span> "print输出一个字符串:"<span style="color: #000000">;
</span><span style="color: #0000ff">print</span> "hello,world";  <span style="color: #008000">//</span><span style="color: #008000">print输出一个字符串</span>
<span style="color: #0000ff">print</span> "<br>"<span style="color: #000000">;
</span><span style="color: #008000">/*</span><span style="color: #008000">start-【print连续输出多个字符串】-start</span><span style="color: #008000">*/</span>

<span style="color: #008000"></span><span style="color: #0000ff">print</span> "print输出多个字符串:"<span style="color: #000000">;
</span><span style="color: #0000ff">print</span> "hello,world","hello,php","hello,python";  <span style="color: #008000">//</span><span style="color: #008000">print输出多个字符串，出错提示：Parse error: syntax error, unexpected ',' in C:\Users\13842\PhpstormProjects\test\print&echo.php on line 14</span><span style="color: #008000">
/*</span><span style="color: #008000">end-【print连续输出多个字符串】-end</span><span style="color: #008000">*/</span><span style="color: #0000ff">print</span> "<br>"<span style="color: #000000">;
</span>?>

屏蔽【print连续输出多个字符串】的代码，结果如下：

如果不屏蔽【print连续输出多个字符串】的代码，出现错误（语法错误）：

（2）echo无返回值，print永远返回1

<span style="color: #000000">php
</span><span style="color: #008000">/*</span><span style="color: #008000">print返回1，echo无返回值</span><span style="color: #008000">*/</span>
<span style="color: #800080">$print_value</span>=<span style="color: #0000ff">print</span> "hello,world<br>";  <span style="color: #008000">//</span><span style="color: #008000">结果：hello,world</span>
<span style="color: #0000ff">print</span> "返回值为<span style="color: #800080">$print_value</span>";   <span style="color: #008000">//</span><span style="color: #008000">结果：返回值为1</span>

<span style="color: #800080">$echo_value</span>=<span style="color: #0000ff">echo</span> "hello,world<br>";   <span style="color: #008000">//</span><span style="color: #008000">出现语法错误</span>
?>

（3）输出方式，带括号和不带括号没有什么区别，这里不做解释。

 

 

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