Foreach ($ stringas $ key => $ val) What is the usage?

Foreach ($ stringas $ key & gt; $ val? If (is_array ($ string) {// if it is an array, this function is executed cyclically.
Foreach ($ string as $ key => $ val ){
$ String [$ key] = daddslashes ($ val, $ force );
}

Read the code analysis article of discuz and read this in the daddslashes function. traverse the array and assign a value to the key? But if I write it like this, I keep reporting errors. why?

Reply to discussion (solution)

You must have read reprinted articles.

> Actually>, it is estimated that the background treats it as a special html character.

Foreach ($ string as $ key => $ val)
Foreach ($ string as $ key => $ val)

You must have read reprinted articles.

> Actually>, it is estimated that the background treats it as a special html character.

Foreach ($ string as $ key => $ val)
Foreach ($ string as $ key => $ val)

I suddenly realized that this was the only thing that caused me to think about it for a long time ....