爆炸到PHP阵列

Question

我正在处理这个程序，在这里我试图分开字符串电子邮件，由'，'，然后我存储在数组中，然后在'foreach'中追加'city' ..

$email='aa,bb,cc,dd'; 
$a=explode(',',$email); 
//echo $a[2]; 
$result=""; 
foreach($a as $v) 
{ 
    $result .= " city = '$v' "; 
    echo $result; 
} 

我得到的结果作为

city = 'aa' city = 'aa' city = 'bb' city = 'aa' city = 'bb' city = 'cc' city = 'aa' city = 'bb' city = 'cc' city = 'dd' 

，但我希望它是,,

city = 'aa' city = 'bb' city = 'cc' city = 'dd' 

是我的代码错了吗？..请指导我..

Answer 1

将echo移出循环，因为您正在循环中构建整个字符串，每次都会回显字符串。

$result=""; 
foreach($a as $v) 
{ 
    $result .= " city = '$v' "; 

} 

    echo $result; // move it here 

Answer 2

你所得到的结果，按您的代码，你echo结果在每个loop执行。

所以为了得到$ result中的最终值，echo它在loop之外。

foreach($a as $v) 
{ 
    $result .= " city = '$v' "; 
} 
echo $result; 

Answer 3

的结果

$email='aa,bb,cc,dd'; 
$a=explode(',',$email); 
//echo $a[2]; 
$result=""; 
foreach($a as $v) 
{ 
    $result = " city = '$v' ";//changed $result .= " city = '$v' "; to $result = " city = '$v' "; 
    echo $result; 
} 

Answer 4

删除字符串连接您的回音$ rresult中的foreach所以你的字符串或变量是重复的。请尝试以下代码：

$email='aa,bb,cc,dd'; 
$a=explode(',',$email); 

$result=""; 
foreach($a as $v) 
{ 
    $result .= " city = '$v' ";  
} 
echo $result; 

Answer 5

删除字符串concate ..

$email='aa,bb,cc,dd'; 
$a=explode(',',$email); 
//echo $a[2]; 
$result=""; 
foreach($a as $v) 
{ 
    $result = " city = '$v' "; // remove string concate.. 
    echo $result; 
} 

另一种方法是foreach循环外回声......

$email='aa,bb,cc,dd'; 
$a=explode(',',$email); 
//echo $a[2]; 
$result=""; 
foreach($a as $v) 
{ 
    $result .= " city = '$v' "; 
} 

echo $result; // echo outside the foreach loop 

输出

city = 'aa' city = 'bb' city = 'cc' city = 'dd'