[英]How can I get only the first two elements of an array by using a foreach loop in PHP?
I have an array like this: 我有一个像这样的数组:
$aMyArray = array(
"bmw"=>"user1",
"audi"=>"user2",
"mercedes"=>"user3"
);
And I only want to show the first two elements bmw=>user1
and audi=>user2
. 我只想显示前两个元素bmw=>user1
和audi=>user2
。 But I want it by using a foreach
loop. 但是我想要通过使用foreach
循环来实现。
If you want the first 2 by name: 如果要按名称输入前两个:
Using in_array
( documentation ) is what you looking for: 您要使用in_array
( 文档 ):
$aMyArray = array("bmw"=>"user1", "audi"=>"user2", "mercedes"=>"user3");
$valuesToPrint = array("bmw", "audi");
foreach($aMyArray as $key => $val) {
if (in_array($key, $valuesToPrint))
echo "Found: $key => $val" . PHP_EOL;
}
If you want the first 2 by index use: 如果要按索引使用前2个,请使用:
init index at 0 and increment in each iteration as: 初始索引为0,每次迭代递增为:
$aMyArray = array("bmw"=>"user1", "audi"=>"user2", "mercedes"=>"user3");
$i = 0;
foreach($aMyArray as $key => $val) {
echo "Found: $key => $val" . PHP_EOL;
if (++$i > 1)
break;
}
Easiest way: 最简单的方法:
$aMyArray=array("bmw"=>"user1","audi"=>"user2","mercedes"=>"user3");
$i=0;
foreach ($aMyArray as $key => $value) {
if($i<2)
{
echo $key . 'and' . $value;
}
$i++;
}
<?php
$aMyArray = array(
"bmw"=>"user1",
"audi"=>"user2",
"mercedes"=>"user3"
);
reset($aMyArray);
echo key($aMyArray).' = '.current($aMyArray)."\n";
next($aMyArray);
echo key($aMyArray).' = '.current($aMyArray)."\n";
$counter = 1;
$max = 2;
foreach ($aMyArray as $key => $value) {
echo $key, "=>", $value;
$counter++;
if ($counter === $max) {
break;
}
}
It is important to break execution to avoid arrays of any size looping until the end for no reason. 重要的是中断执行,以避免无缘无故地循环直到最后的任何大小的数组。
I know you're asking how to do it in a foreach
, but another option is using array travelling functions current
and next
. 我知道你在问如何在foreach
做到这一点,但另一个选择是使用current
和next
数组移动函数。
$aMyArray = array(
"bmw"=>"user1",
"audi"=>"user2",
"mercedes"=>"user3"
);
$keys = array_keys($aMyArray);
//current($array) will return the value of the current record in the array. At this point that will be the first record
$first = sprintf('%s - %s', current($keys), current($aMyArray)); //bmw - user1
//move the pointer to the next record in both $keys and $aMyArray
next($aMyArray);
next($keys);
//current($array) will now return the contents of the second element.
$second = sprintf('%s - %s', current($keys), current($aMyArray)); //audi - user2
You are looking for something like this 您正在寻找这样的东西
$aMyArray = array(
"bmw"=>"user1",
"audi"=>"user2",
"mercedes"=>"user3"
);
foreach($aMyArray as $k=>$v){
echo $v;
if($k=='audi'){
break;
}
}
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