What does the ^ circumflex accent/caret/circumflex in the composer version number mean?

Encountered when using composer Mailgun.
"mailgun/mailgun-php": "^1.8"

I've encountered ^ this symbol before, but I haven't looked into it. The answer is now not found by searching.

Here (http://docs.phpcomposer.com/01-basic-usage.html) said the role of ~, but did not say ^ .

^Several of the names found:

• Circumflex Accent

• de-font

• Circumflex (also referred to as Caron in some places other than Wikipedia)

But I do not know the function of this symbol. Especially on the software version number.

Ask.

Reply content:

Encountered when using composer Mailgun.
"mailgun/mailgun-php": "^1.8"

I've encountered ^ this symbol before, but I haven't looked into it. The answer is now not found by searching.

Here (http://docs.phpcomposer.com/01-basic-usage.html) said the role of ~, but did not say ^ .

^Several of the names found:

• Circumflex Accent

• de-font

• Circumflex (also referred to as Caron in some places other than Wikipedia)

But I do not know the function of this symbol. Especially on the software version number.

Ask.

It's for the control version.
Detailed explanations are as follows:
Https://getcomposer.org/doc/articles/versions.md#caret
Example:
^1.2.3 means >=1.2.3 <2.0.0
^0.3 means >=0.3.0 <0.4.0

The first guess is the same as the regular symbol, indicatingmatch beginning of 1.8

Specifically, I'll look for ... Guessing errors

======================, look downstairs, =============================.

