缺少排序数组-rsort-PHP的键

我正在对以下数组进行rsort

$list_array = array("a1"=>$a1,"a2"=>$a2,"a3"=>$a3,"a4"=>$a4,"a5"=>$a5,"a6"=>$a6,"a7"=>$a7,"a8"=>$a8,"a9"=>$a9,"a10"=>$a10,"a11"=>$a11,"a12"=>$a12,"a13"=>$a13,"a14"=>$a14,"a15"=>$a15,"a16"=>$a16, "a17"=>$a17,"a18"=>$a18,"a19"=>$a19,"a20"=>$a20,"a21"=>$a21);

rsort( $list_array, SORT_NUMERIC );

print_r( $list_array );

结果

Array ( [0] => 32.87 [1] => 8.48 [2] => 8.34 [3] => 8.33 [4] => 7.85 [5] => 5.77 [6] => 3.75 [7] => 2.42 [8] => 1.24 [9] => 0.47 [10] => 0.09 [11] => 0.06 [12] => 0.01 [13] => 0.01 [14] => 0.01 [15] => 0.01 [16] => 0.01 [17] => 0 [18] => 0 [19] => 0 [20] => 0 )

钥匙不见了

如何修复此问题以将键保留在输出中？

您需要使用而不是rsort

按相反顺序对数组排序并保持索引关联

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如果我使用arsort，我如何在不知道标题顺序的情况下打印前3项？根据代码切片的需要，您可以做一些事情，例如使用计数器等。但这与您提出的问题完全不同。