How to assign value to array in php+

php How to assign values ​​to arrays

In PHP, arrays are a very common and important data type. In programming, we usually need to assign an initial value to an array or change the values ​​in the array. This article will introduce how to assign an initial value to an array and change the value in the array in PHP.

1. Assign an initial value to an array

In PHP, you can assign a value to an array in the following ways:

1. Use the array() function:

The array() function is PHP's built-in function, which can be used to define an array. The following is a sample code for assigning an initial value to an array:

<?php $arr = array(1, 2, 3); 
print_r($arr); 
?>

The above code creates an array $arr, which contains elements 1, 2 and 3, and outputs it as the following result through the print_r() function:

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
)

2. Use square brackets "[]":

Another way to define an array is to use square brackets "[]", as follows:

<?php $arr[0] = 'apple';
$arr[1] = 'banana';
$arr[2] = 'orange';
print_r($arr); 
?>

In the above code, we use square brackets to set the 0th, 1st and 2nd elements of the array $arr, which are 'apple', 'banana' and 'orange' respectively. The running results are as follows:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)

2. Change the value in the array

In PHP, to change the value in the array, you can use subscripts. The following is a sample code for changing the values ​​in the array:

<?php $arr = array(1, 2, 3, 4, 5);
$arr[1] = 'apple';
$arr[3] = 'banana';
print_r($arr); 
?>

In the above code, we change the elements in the array by assigning values ​​to subscripts 1 and 3. The result is as follows:

Array
(
    [0] => 1
    [1] => apple
    [2] => 3
    [3] => banana
    [4] => 5
)

It should be noted that if you use a non-integer subscript, PHP will automatically convert it to an integer, as follows:

<?php $arr = ['a'=>1, 'b'=>2, 'c'=>3];
$arr['b'] = 'apple';
$arr['d'] = 'banana';
print_r($arr); 
?>

In the above code, we used a string 'apple' and 'banana' are used as subscripts, but PHP will convert these strings into numeric subscripts. The numeric subscript of 'apple' is 0, and the numeric subscript of 'banana' is 1. The final result is as follows:

Array
(
    [a] => 1
    [b] => apple
    [c] => 3
    [d] => banana
)

Summary:

Through the above examples, we can see that assigning an initial value to an array and changing the elements in the array are very simple, as long as you remember the array subscript Just use the method. In actual programming, we need to flexibly use arrays in PHP to achieve better program effects.

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