php 如果 $variable = 0 不起作用
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If $variable = 0 not working
提问by GiantDuck
if($_POST['user_admin'] = 0){ $acct_type = "a standard"; }
elseif($_POST['user_admin'] = 1){ $acct_type = "an administrator"; }
echo $acct_type;
echo $_POST['user_admin'];
Whether $_POST['user_admin']is 0 or 1, $acct_typestill returns "an administrator" Why?
不管$_POST['user_admin']是0还是1，$acct_type还是返回“管理员”为什么？
回答by Tim Dearborn
You need to use "==" when comparing variables.
比较变量时需要使用“==”。
if($_POST['user_admin'] == 0){ $acct_type = "a standard"; }
elseif($_POST['user_admin'] == 1){ $acct_type = "an administrator"; }
echo $acct_type;
echo $_POST['user_admin'];
回答by Ian
It should be
它应该是
if $variable == 0
回答by admoghal
you are assigning value with = you should use $variable == 0 to compare the value
你用 = 赋值你应该使用 $variable == 0 来比较值
回答by janenz00
You are on the first of 10 common PHP mistakes to avoid:-)
您是要避免的10 个常见 PHP 错误中的第一个:-)
$_POST['user_admin'] = 0
$_POST['user_admin'] = 1
are both assignments. PHP evaluates whether the final assigned expression is true or false after assigning the value to $_POST['user_admin'] . So, the first one will evaluate to false since the assigned value is 0, and the second one will evaluate to true since the assigned value is 1.
都是任务。PHP 在将值分配给 $_POST['user_admin'] 后评估最终分配的表达式是真还是假。因此，第一个将评估为 false，因为分配的值为 0，第二个将评估为 true，因为分配的值为 1。
As everyone pointed out, you have to use "==" instead of "=" for conditional statements.
正如每个人所指出的，对于条件语句，您必须使用“==”而不是“=”。
