echo <<<END This uses the "here document" syntax to output multiple lines with $variable interpolation. Note that the here document terminator must appear on a line with just a semicolon. no extra whitespace! END;
// Because echo does not behave like a function, the following code is invalid. ($some_var) ? echo "true" : echo "false";
// However, the following examples will work: ($some_var) ? print "true" : print "false"; // print is also a construct, but // it behaves like a function, so // it may be used in this context. echo $some_var ? "true": "false"; // changing the statement around ?>
以下是官方手册说明: Definition and Usage 定义和用法 The echo() function outputs one or more strings. echo()函数的作用是:输出一个或多个字符串。 Syntax 语法 echo(strings) Parameter参数 Description描述 strings Required. One or more strings to be sent to the output 必要参数。指定一个或多个需要被发送到结果中的字符串 Tips and Notes 提示和注意点 Note: The echo() function is not actually a function, so you are not required to use parentheses with it. However, if you want to pass more than one parameter to echo(), using parentheses will generate a parse error. 注意:echo()函数不是一个真正意义上的函数,所以你没有必要一定去使用它。如果你想把多于一个的参数传递给echo()函数,那么使用圆括号“()”将产生错误。 Tip: The echo() function is slightly faster than print(). 提示:echo()函数相当于print()函数的简化版本。 Tip: The echo() function has the following shortcut syntax. See example 5. 提示:echo()函数包含下面的简便写法。具体见:案例5。 Example 1 案例1 复制代码 代码如下: <?php $str = "Who"s Kai Jim?"; echo $str; echo "<br />"; echo $str."<br />I don"t know!"; ?>
The output of the code above will be: 上述代码将输出下面的结果: Who"s Kai Jim?Who"s Kai Jim?I don"t know!
The output of the code above will be: 上述代码将输出下面的结果: This string was made with multiple parameters
Example 4 案例4 Difference of single and double quotes. Single quotes will print the variable name, not the value: 区别单引号(")和双引号(”)的不同。单引号将输出变量名,而不是变量的值: 复制代码 代码如下: <?php $color = "red"; echo "Roses are $color"; echo "<br />"; echo "Roses are $color"; ?>
The output of the code above will be: 上述代码将输出下面的结果: Roses are redRoses are $color
Example 5 案例5 Shortcut syntax: 简写(捷径)语法: 复制代码 代码如下: <html><body> <?php $color = "red"; ?><p>Roses are <?=$color?></p></body></html>