How to get a single value from an array in php

How to extract a single value from an array in php. Below, I will share with you a method for extracting a single value from an array in php. It has a good reference value and I hope it can help you.

1. Array arr

var_dump(arr) has the following values:

array (size=3)
 'delete' => 
 array (size=3)
  0 => string 'HBSFlyRecode20170222-101501.txt' (length=31)
  1 => string 'HBSFlyRecode20170222-105502.txt' (length=31)
  2 => string 'HBSFlyRecode20170222-108803.txt' (length=31)
 'new' => 
 array (size=3)
  0 => string 'HBSFlyRecode20170223-101504.txt' (length=31)
  1 => string 'HBSFlyRecode20170223-105505.txt' (length=31)
  2 => string 'HBSFlyRecode20170223-108806.txt' (length=31)
 'old' => 
 array (size=3)
  0 => string 'HBSFlyRecode20170221-101507.txt' (length=31)
  1 => string 'HBSFlyRecode20170221-105508.txt' (length=31)
  2 => string 'HBSFlyRecode20170221-108809.txt' (length=31)

echo $arr['old'][0];
打印出: HBSFlyRecode20170221-101507.txt

But if arr is in object form, the print result is as follows:

var_dump(arr)
object(stdClass)[1]
 public 'delete' => 
 array (size=3)
  0 => string 'HBSFlyRecode20170222-101501.txt' (length=31)
  1 => string 'HBSFlyRecode20170222-105502.txt' (length=31)
  2 => string 'HBSFlyRecode20170222-108803.txt' (length=31)
 public 'new' => 
 array (size=3)
  0 => string 'HBSFlyRecode20170223-101504.txt' (length=31)
  1 => string 'HBSFlyRecode20170223-105505.txt' (length=31)
  2 => string 'HBSFlyRecode20170223-108806.txt' (length=31)
 public 'old' => 
 array (size=3)
  0 => string 'HBSFlyRecode20170221-101507.txt' (length=31)
  1 => string 'HBSFlyRecode20170221-105508.txt' (length=31)
  2 => string 'HBSFlyRecode20170221-108809.txt' (length=31)

You cannot use $arr['old'][0] to get the value, you can use the arr object The value of the foreach method that is common to arrays:

function getValue($arr){
 foreach($arr as $key => $value){
  if(is_array($value)){
   getValue($value);
  }else{
   echo $value."<br>";
  }
 }
}

If arr is in object form, you can convert the object into array form. Here is an example A shortcut:

1. $object_json = json_encode($arr); what you get is the object

$json = json_encode($arr,true); what you get It is pure json

2. What json_decode($object_json) and json_decode($json) get is an array object

json_decode($object_json,true) and json_decode($json,true) It’s an array

To sum up, you can convert an array object into an array:

arr=jsondecode(jsonencode(arr=jsondecode(jsonencode(arr,true),true);

project I found this problem in . It is recommended that when converting json and array in php, you should add true to the second parameter of json_encode() and json_decode(), that is:

##

json_encode(arr,true);jsondecode(arr,true);jsondecode(json,true);

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