Weird PHP syntax, solving!

Find a sentence that PHP uses to determine whether a string is a bunch of buns rather weird.

Look at the following statement:

echo "A1:". (Strpos ("CSD", "C")). "
";
echo "A2:". (Strpos ("CSD", "C") >=0). "
";
echo "B1:". (Strpos ("CSD", "H", 0)). "
";
echo "B2:". (Strpos ("CSD", "H", 0) >=0). "
";

if (Strpos ("abc", "a") >=0)
{
echo "A in ABC". "
";
}
Else
{
echo "A not in ABC". "
";
}

if (Strpos ("abc", "U") >=0)
{
echo "u in abc". "
";
}
Else
{
echo "U not in abc". "
";
}

if (Strpos ("A", "abc") >=0)
{
echo "ABC in a". "
";
}
Else
{
echo "ABC not in a". "
";
}

if (Strpos ("U", "abc") >=0)
{
echo "ABC in U". "
";
}
Else
{
echo "ABC not in U". "
";
}

Strpos

The results displayed

a1:0
A2:1
B1:
B2:1
A in ABC
U in ABC
ABC in a
ABC in U

Definition and usage

The Strpos () function returns the position of the first occurrence of a string in another string.

If the string is not found, false is returned.

Grammar

Strpos (String,find,start)

Parameter description

String	Necessary. Specifies the string to be searched.
Find	Necessary. Specifies the character to find.
Start	Optional. Specify where to start the search.

Ask, here, for example I want to judge the string "abc" contains "a", which method is better?

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