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PHP learning array

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Release： 2023-03-23 11:20:02

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This article will share with you the knowledge of arrays in PHP. Friends in need can refer to it

Arrays are not very simple
int a[1100000]
But PHP is not like this

<?php
    $n=1;    $a=array(array(array()));    $s=array();    $s[1]="S30408";    $a[1][1][1]=0;$a[1][1][2]=1.05;    $a[1][2][1]=0;$a[1][2][2]=2.04;    $a[1][3][1]=7.90;$a[1][3][2]=11.15;    $a[1][4][1]=17.80;$a[1][4][2]=20.20;    $a[1][5][1]=0;$a[1][5][2]=0.09;    $a[1][6][1]=0;$a[1][6][2]=0.055;    $a[1][7][1]=0;$a[1][7][2]=0.035;?>

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This is a three-dimensional array, is it a little troublesome?
Let’s start with one-dimensional arrays.

<?php
    $s=array();/*每一个array就是一个维度*/
    $s[1]=100;$s[2]=200;    echo $s[1]+$s[2];?>

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PHP learning array
This is an array. I have a full arrangement of php

<?php
    $v=array();    $a=array();    function dfs($k){
        global $v,$a,$n;        if($k==$n+1){            for($i=1;$i<n;$i++){                echo $v[$i]," ";
            }            echo $v[$n],"<br>";
        }        else{            for($i=1;$i<=n;$i++){                if($v[$i]==true){                    $v[$i]=false;                    $a[$k]=$i;
                    dfs($k+1);                    $v[$i]=true;
                }
            }
        }
    }
    dfs(5);?>

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This is to find the full arrangement of 5.
It seems a little wrong, but don’t be afraid.
Just look at the example
Just connect the two-dimensional one to the very simple one
That’s it

$s=array(array());

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That’s it
I will update a chapter tomorrow, what will I talk about?
Let’s talk about some operation loops.

Isn’t an array very simple?
int a[1100000]
But php is not like this

<?php
    $n=1;    $a=array(array(array()));    $s=array();    $s[1]="S30408";    $a[1][1][1]=0;$a[1][1][2]=1.05;    $a[1][2][1]=0;$a[1][2][2]=2.04;    $a[1][3][1]=7.90;$a[1][3][2]=11.15;    $a[1][4][1]=17.80;$a[1][4][2]=20.20;    $a[1][5][1]=0;$a[1][5][2]=0.09;    $a[1][6][1]=0;$a[1][6][2]=0.055;    $a[1][7][1]=0;$a[1][7][2]=0.035;?>

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This is a three-dimensional array, is it a little troublesome?
Let’s start with one-dimensional arrays.

<?php
    $s=array();/*每一个array就是一个维度*/
    $s[1]=100;$s[2]=200;    echo $s[1]+$s[2];?>

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PHP learning array
This is an array. I have a full arrangement of php

<?php
    $v=array();    $a=array();    function dfs($k){
        global $v,$a,$n;        if($k==$n+1){            for($i=1;$i<n;$i++){                echo $v[$i]," ";
            }            echo $v[$n],"<br>";
        }        else{            for($i=1;$i<=n;$i++){                if($v[$i]==true){                    $v[$i]=false;                    $a[$k]=$i;
                    dfs($k+1);                    $v[$i]=true;
                }
            }
        }
    }
    dfs(5);?>

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This is to find the full arrangement of 5.
It seems a little wrong, but don’t be afraid.
Just look at the example
Just connect the two-dimensional one to the very simple one
That’s it