(click to copy)
Char 
Unicode name <control-0004>
Unicode group Basic Latin
Unicode Code Point U+4
HTML Entity (decimal) &#4;
HTML Entity (hex) &#x4;
How to type in Microsoft Windows Alt + 4
How to type in Microsoft Office write 4 then press Alt + X
How to type in Microsoft Office write U+4 then press Alt + X
How to type in Apple Mac Hold Alt, type 4 then release
How to type in Apple Mac Hold Option, type 4 then release
UTF-8 (hex) 0x04
UTF-8 (octal) 4
UTF-8 (binary) 00000100
UTF-16 (hex) 0x0004
UTF-16 (decimal) 4
UTF-32 (hex) 0x00000004
UTF-32 (decimal) 4
How to display in C/C++/Java "\u4"
How to type in Python u"\u4"