If think looks at the tutorial, is there a kind of "ectopic or encryption" in php? As shown in the figure, why can't I use Baidu?

That is what follows $ value. how can we use the symbol? I haven't found a similar theme on the keyboard for a long time, so I can't write anything about it.

Is the one behind $ value.

In other words, how can the symbols be played out? I haven't found a similar theme on the keyboard for a long time, so I can't write anything about it.

Reply content:

Is the one behind $ value.

In other words, how can the symbols be played out? I haven't found a similar theme on the keyboard for a long time, so I can't write anything about it.

The number 6 on the keyboard's primary key

Bitwise OR operator

Shift + number 6 can be played if it is not in the keypad area ^

Bit operations, look at C. otherwise you will not understand it.