如何读取PHP中是否选中了复选框（） _PHP表单

使用isset()函数
isset()函数是PHP中的内置函数, 它检查是否设置了变量, 并且该变量不是NULL。此函数还检查声明的变量, 数组或数组键是否具有空值, 如果存在, 则isset()返回false, 在所有其他可能情况下返回true。可以使用isset()函数解决此问题。
语法如下：

bool isset( $var, mixed )

描述：此函数接受多个参数。该函数的第一个参数是$ var。此参数用于存储变量的值。
程序：

< ? php if(isset($_GET['submit'])) { $var = $_GET['option1']; if(isset($var)) { echo "Option 1 submitted successfully"; } } ?> < html lang = "en"> < head> < title> srcmini Example< /title> < meta charset = "utf-8"> < meta name = "viewport" content = "width=device-width, initial-scale=1"> < link rel = "stylesheet" href = "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"> < style> .gfg { font-size:40px; font-weight:bold; color:green; } body { text-align:center; } < /style> < /head> < body> < div class = "container"> < div class = "gfg"> srcmini< /div> < h2> Form control: checkbox< /h2> < p> The form below contains one checkbox.< /p> < form method = "get"> < div class = "checkbox"> < label> < input type = "checkbox" name = "option1" value = "http://www.srcmini.com/Option 1"> Option 1< /label> < label> < button name = "submit" value = 'http://www.srcmini.com/true' class = "btn btn-default"> SUBMIT< /button> < /div> < /form> < /div> < /body> < /html>

输出如下：

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【如何读取PHP中是否选中了复选框（）】使用empty()函数
empty()函数是PHP中的内置函数, 用于检查变量是否为空。
语法如下：

bool empty( $var )

描述：此函数确定变量是否为空。
例子：

< ? php if(!empty($_GET['submit'])) { $var = $_GET['option1']; if(isset($var)){ echo "Option 1 submitted successfully"; } } ?> < !DOCTYPE html> < html lang = "en"> < head> < title> srcmini Example< /title> < meta charset = "utf-8"> < meta name = "viewport" content = "width=device-width, initial-scale=1"> < link rel = "stylesheet" href = "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"> < script src = "https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"> < /script> < script src = "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"> < /script> < style> .gfg { font-size:40px; font-weight:bold; color:green; } body { text-align:center; } < /style> < /head> < body> < div class = "container"> < div class = "gfg"> srcmini< /div> < h2> Form control: checkbox< /h2> < p> The form below contains one checkbox.< /p> < form method = "get"> < div class = "checkbox"> < label> < input type = "checkbox" name = "option1" value = "http://www.srcmini.com/Option 1"> Option 1< /label> < label> < button name = "submit" value = "http://www.srcmini.com/true" class = "btn btn-default"> SUBMIT< /button> < /div> < /form> < /div> < /body> < /html>

输出如下：