Usage of foreach () loop in PHP

Here, array_name is the name of the array to be traversed. in each loop, the value of the current element of the array_name array is assigned to $ value, and the downloading inside the array is moved one step down, that is, the next element is returned in the next loop.

Loop foreach () is often used in PHP. The following describes how to use this loop:

Foreach () has two usage methods:

1: foreach (array_name as $ value)
{
Statement;
}

Here, array_name is the name of the array to be traversed. in each loop, the value of the current element of the array_name array is assigned to $ value, and the downloading inside the array is moved one step down, that is, the next element is returned in the next loop.

2: foreach (array_name as $ key => $ value)
{
Statement;
}

The difference between this method and the first method is that there is an extra $ key, that is, in addition to assigning the value of the current element to $ value, the key value of the current element is also assigned to the variable $ key in each loop. The key value can be either a lower mark value or a string. For example, "0" in book [0] = 1 and "id" in book [id] = "001 ".