ℍ𝕠𝕤𝕥𝕚𝕟𝕘-𝕚𝕟-𝕛𝕒𝕧𝕒𝕤𝕔𝕣𝕚𝕡𝕥

𓂀 𝕀'𝕞 𝕦𝕡𝕝𝕠𝕒𝕕𝕚𝕟𝕘 𝕞𝕪 𝕨𝕠𝕣𝕜. 𓂀

𝙏𝙝𝙚 𝙢𝙤𝙨𝙩 𝙖𝙨𝙠 𝙦𝙪𝙚𝙨𝙩𝙞𝙤𝙣 𝙞𝙣 𝙞𝙣𝙩𝙚𝙧𝙫𝙞𝙚𝙬.

@1.>𝓦𝓱𝓪𝓽 𝓲𝓼 𝓱𝓸𝓲𝓼𝓽𝓲𝓷𝓰?

=>ʜᴏɪꜱᴛɪɴɢ ɪɴ ᴊᴀᴠᴀꜱᴄʀɪᴘᴛ ɪꜱ ᴛʜᴇ ʙᴇʜᴀᴠɪᴏʀ ʙʏ ᴡʜɪᴄʜ ᴛʜᴇ ᴅᴇᴄʟᴀʀᴀᴛɪᴏɴ ᴏꜰ ᴠᴀʀɪᴀʙʟᴇꜱ ᴀɴᴅ ꜰᴜɴᴄᴛɪᴏɴꜱ ᴀʀᴇ ᴍᴏᴠᴇᴅ ᴛᴏ ᴛʜᴇ ᴛᴏᴘ. ᴛʜɪꜱ ᴍᴇᴀɴꜱ ᴛʜᴀᴛ ᴛʜᴇ ᴠᴀʀɪᴀʙʟᴇ ᴏʀ ꜰᴜɴᴄᴛɪᴏɴ ᴅᴇᴄʟᴀʀᴀᴛɪᴏɴ ɴᴇᴇᴅ ɴᴏᴛ ʙᴇ ᴅᴏɴᴇ ʙᴇꜰᴏʀᴇ ɪɴɪᴛɪᴀʟɪᴢɪɴɢ ᴀɴᴅ ᴄᴀʟʟɪɴɢ ᴛʜᴇᴍ. ʜᴏɪꜱᴛɪɴɢ ᴡɪʟʟ ʜᴀᴘᴘᴇɴ ᴏɴʟʏ ɪꜰ ᴠᴀʀ ɪꜱ ᴜꜱᴇᴅ ꜰᴏʀ ᴅᴇᴄʟᴀʀᴀᴛɪᴏɴ ᴀɴᴅ ɴᴏᴛ ᴡɪᴛʜ ᴄᴏɴꜱᴛ ᴏʀ ʟᴇᴛ ᴅᴇᴄʟᴀʀᴀᴛɪᴏɴꜱ.

𝐸𝓍𝒶𝓂𝓅𝓁𝑒 => // 𝘱𝘳𝘰𝘨𝘳𝘢𝘮 𝘵𝘰 𝘥𝘪𝘴𝘱𝘭𝘢𝘺 𝘷𝘢𝘭𝘶𝘦 𝘤𝘰𝘯𝘴𝘰𝘭𝘦.𝘭𝘰𝘨(𝘢); 𝘷𝘢𝘳 𝘢 = 5; // var is the keyword that tells JavaScript you're declaring a variable that globally-scoped.

Show in a this case the output will be come undefined because we are executing before initalizing.