My Samsung Galaxy phone is not connecting to Wi-Fi. How can I troubleshoot wi-fi issues?

Before you start reading, keep in mind that as settings and software versions can differ slightly, instructions may differ slightly from device to device. You can find some first-to-do troubleshooting steps here:
• Restarting the router and phone can sometimes fix the connection. Leave your router off for a moment, then restart it. After that, restart your phone.
• Find and delete the Wi-Fi network you're trying to connect to in your phone's settings. Try connecting again with your password.
• Make sure your phone's Airplane mode is off. Airplane mode disables Wi-Fi and all wireless capabilities.
• Reset network settings: Go to "Reset" or "Advanced settings" in your phone's settings to reset your network. This may aid connection restoration.
• Make sure your phone has the latest software. Updates sometimes fix Wi-Fi issues.
• Connect to another Wi-Fi network: Switch to a public or home router Wi-Fi network. This will help you determine if the problem is with your network or device.
• If all else fails, factory reset your smartphone. Make a backup before continuing as this will erase all your data.
• Reach customer service: Samsung support or an official service center can help if none of the above methods work.
• Your phone or router may have a physical flaw if it won't connect to Wi-Fi after trying everything above. For diagnosis and repair, visit a service center.