Question

我有这段代码：

If(!isset($a) || empty($a))
{
    // code to run when $a not set or empty;
}
Elseif ($a==0)
{
     //code to run when $a is equal 0
}
Else
{
      //code to run in all other scenarios
}

问题是，当$ a等于0时，空（$ a）为真且第一个代码运行。我需要第二个运行。我该怎么做？

Answer 1

if (isset($a) && $a == 0)
    {
    //code to run when $a is equal 0
    }
elseif (empty($a))
    {
    // code to run when $a not set or empty;
    }
else
    {
    //code to run in all other scenarios
    }

Answer 2

替换它并尝试

If(!isset($a) || $a=='') 
{
// code to run when $a not set or empty;
}
Elseif ($a==0)
{
     //code to run when $a is equal 0
}
Else
{
      //code to run in all other scenarios
}

Answer 3

试试这个：

if((!isset($a) || empty($a)) && $a !== 0)
{
    // code runs when $a not set or empty and $a is not 0;
}
elseif ($a === 0)
{
     //code runs when $a is equal 0
}
else
{
      //code runs in all other scenarios
}

<强>更新更改为类型安全比较。

Answer 4

我找到了解决方案：

if (!isset($a) || (empty($a) && $a!==0))
{
    //run code if $a is not set or is empty
}
elseif ($a===0)
{
    //run code if $a is 0;
}
else
{
    //all other scenarios
}

Answer 5

当0（0为整数）时，Empty函数返回false。

所以你的代码应该是

If(!isset($a))
{
    // code to run when $a not set or empty;
}
Elseif ($a==0)
{
     //code to run when $a is equal 0
}
Else
{
      //code to run in all other scenarios
}

如果条件和空变量

5 个答案: