Why is using var_dump more suitable than echo for testing variable content?

When testing variable content in PHP, using var_dump is more suitable than echo because var_dump provides detailed information about the variable, including its type and value. This can be especially helpful when dealing with complex data structures or debugging code. Echo, on the other hand, simply outputs the value of the variable as a string, which may not provide enough information for thorough testing.

$variable = "Hello, world!";
var_dump($variable);