计算之前的二维数组:$arr = array(
array(vw => 21, n => 0),
array(vw => 34, n => 0),
array(vw => 44, n => 0),
array(vw => 65, n => 0),
);
计算之后的数组:$arr = array(
array(vw => 21, n => 21),
array(vw => 34, n => 13),
array(vw => 44, n => 10),
array(vw => 65, n => 21),
);
array(vw => 21, n => 0),
array(vw => 34, n => 0),
array(vw => 44, n => 0),
array(vw => 65, n => 0),
);
计算之后的数组:$arr = array(
array(vw => 21, n => 21),
array(vw => 34, n => 13),
array(vw => 44, n => 10),
array(vw => 65, n => 21),
);
foreach($i=1;$i<count($arr);$i++)
{
$arr[$i]['n']=$arr[$i]['vw']-$arr[$i-1]['vw'];
}
$arr = array(
array(vw => 21, n => 0),
array(vw => 34, n => 0),
array(vw => 44, n => 0),
array(vw => 65, n => 0),
);foreach($arr as $key =>$narr){
if($key=='0'){
$arr[$key][n]=$arr[$key][vw];
}
$arr[$key][n]=$arr[$key][vw]-$arr[$key-1][vw]; }
print_r($arr);
array(vw => 21, n => 0),
array(vw => 34, n => 0),
array(vw => 44, n => 0),
array(vw => 65, n => 0),
);
foreach ($arr as $key=>$val) {
if($key===0){
$arr[$key]['n']=$arr[$key]['vw'];
}else{
$arr[$key]['n']=$arr[$key]['vw']-$arr[$key-1]['vw'];
}
}
print_r($arr);
if($key===0){
$arr[$key]['n']=$arr[$key]['vw'];
}else{
$arr[$key]['n']=$arr[$key]['vw']-$arr[$key-1]['vw'];
}
}
print_r($arr);兄弟~还要多学习哦
array('vw' => 21, 'n' => 0),
array('vw' => 34, 'n' => 0),
array('vw' => 44, 'n' => 0),
array('vw' => 65, 'n' => 0),
);
$i = count($arr);
while ($i && $arr[--$i]['n'] = $arr[$i]['vw'] - $arr[$i - 1]['vw']);print_r($arr);
array(vw => 21, n => 0),
array(vw => 34, n => 0),
array(vw => 44, n => 0),
array(vw => 65, n => 0),
);
function chk(&$a,$k,$all){
$a['n'] = $a['vw']-($k>0?$all[$k-1]['vw']:0);
}
array_walk($arr,'chk',$arr);
print_r($arr);