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PHP traverses the array foreach each() list() method summary

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Release: 2016-07-25 08:56:19
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  1. foreach($array as $value){ //$array is the array to be traversed, $value is the pointer pointing to the current value of the array, as plays the role of assignment
  2.   code to executed;
  3. }
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foreach statement can also get the key name of the array, as follows:

  1. foreach($array as $key => $value){
  2.   echo $key "-" $value. "
    ";
  3. }
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two , echo() function The function of each() is to split the key-value pairs of the current element of the array into a new array, and use the next element as the current element. For example, the 'Robert'=>'Bob' key-value pair in Array(...,'Robert'=>'Bob',...) is split into Array([1]=>'Bob',[value] =>'Bob',[0]=>'Robert',[key]=>'Robert') array, split into two sets (a total of four key-value pairs) to return, the serial number pairs of 0 and 1, key and value name-value pairs, just use one of them.

Example:

  1. $prices=Array('Tries' => 100, 'Oil' => 10, 'Spank Plugs' => 4);
  2. while($elements = each( $prices)){
  3.  echo $elements['key']; //echo $elements[0];
  4.  echo " - ";
  5.  echo $elements['value']; //echo $element[1];
  6. echo "
    ";
  7. }
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output result: Tires-100 Oil-10 Spank Plugs-4

Three, the list() function traverses the array The list() function can be used to decompose an array into a series of values. list() is often used together with each(). But list() can also be used without each(), for example: list($key, $value) = explode(":", $v); list($key, $value) = each($array); //$key, $value can be named arbitrarily. This sentence assigns the current elements at positions 0 and 1 of the array returned by each to the $key and $value variables. example:

  1. $prices=Array('Tries' => 100, 'Oil' => 10, 'Spank Plugs' => 4);
  2. while(list($product, $prices) = each($prices);){
  3.  echo $product "-" $prices;
  4.  echo "
    ";
  5. }
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Output result: Tires-100 Oil-10 Spank Plugs-4

Another implementation method:

  1. $prices=Array('Tries' => 100, 'Oil' => 10, 'Spank Plugs' => 4);
  2. list($product, $price ) = $each($prices);
  3. echo "$product - $price"; //Output the first array
  4. $next = $next($prices); //Move the pointer back
  5. echo $next;
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source:php.cn
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