How to remove the first digits of an array in php

php method to remove the first N digits of an array: 1. Use the array_slice() function. You only need to set the second parameter of the function to N. The syntax is "array_slice($arr,N);" ; 2. To use the array_splice() function, just set the second parameter of the function to 0, and set the third parameter start to "N-array length". The syntax is "array_splice($arr,0,(N -array length));".

The operating environment of this tutorial: windows7 system, PHP8 version, DELL G3 computer

php intercepts the last few digits of the array Element

1. Use array_slice() function

array_slice() function is a function provided by PHP to intercept arrays. It can be obtained from Extract a fragment from the array. The syntax is as follows:

array array_slice ( array $arr , int $start [, int $length = NULL [, bool $preserve_keys = false ]] )

Parameter description:

• arr represents the array to be intercepted.
• start indicates the starting position (subscript) of interception:
  • If start is a positive number, interception will be performed from front to back.
  • If start is a negative number, start from the position -start from the end of arr and intercept from back to front. For example -2 means start from the second to last element of the array.
• length is an optional parameter, indicating the intercepted length:
  • If length is a positive number, it indicates the number of intercepted elements;
  • If length If it is a negative number, then the intercepted fragment will end at the length position from the end of the array;
  • If it is omitted, it will start from the start position and continue to the end of the array.
• preserve_keys is an optional parameter that specifies whether to retain the original key name. The default is false, that is, not retained; if set to true, the original key name will be retained.

If you want to use the array_slice() function to delete the first N elements of the array, you only need to set the second parameter of the function to N.

Example: Remove the first 5 digits of the array

<?php
header("Content-type:text/html;charset=utf-8");
$arr=array(10,12,20,25,24,22,34,56,78,90);
echo "原数组：";
var_dump($arr);
echo "去掉数组前5位：" ;
$result = array_slice($arr,5); 
var_dump($result);

?>

Output result

2 , use the array_splice() function

When the array_splice() function deletes some elements of the array, it will form these deleted elements into a new array, and then return this new array; therefore array_splice() Functions can be used to intercept array fragments.

Just set the second parameter of the array_splice() function to 0, and set the third parameter start to a negative value (-N) to intercept the last N elements of the array; in other words, the third The first parameter start is set to (N-array length) to remove the first N bits of the array.

Example

<?php
header("Content-type:text/html;charset=utf-8");
$arr = array(10,12,20,25,24);
echo "原数组：";
var_dump($arr);
echo "去掉数组前2位：" ;
array_splice($arr,0,(2-5));
var_dump($arr);

?>

Output result

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