Dannyboy questions

• Constraint symbol vs foreign key index name -> what's the difference?
• PHP - Why is DateTime object copied by reference in my code? [duplicate]
• How CSS line-height is measured?
• What is the preg_replace regex to replace this HTML tag?
• python using __init__ vs just defining variables in class - any difference?
• some confusion on git pull vs git-fetch [duplicate]
• Why can't I tab into CSS3 checkboxes?
• when initializing PDO - should I do: charset=UTF8 or charset=UTF8MB4?

Dannyboy answers