为什么echo不会打印文本的第一部分

Question

Why this only print out "-1". What happens to the first part of the text.

echo "2 results of this " .    "Apples" <=> "bananas";

Thanks

Answer 1

. has higher precedence than <=>, so it's parsed as if you'd written:

echo ("2 results of this " . "Apples") <=> "bananas";

which is equivalent to:

echo "2 results of this Apples" <=> "bananas";

So it's comparing these two strings and printing just the result.

Add parentheses to get what you want:

echo "2 results of this " . ("Apples" <=> "bananas");