CJam, 3 characters

Removed ) as per Martin Ender's suggestion

'(~ 

Similar to the Python one given as an example.

Using '~ you can obtain the ~ character. Then using (, you can decrement it in order to get whatever character you want (~ is the last printable ASCII character). ~ evals any string as normal CJam code. Strings can be constructed by obtaining the character [ (through decrementing ~), eval'ing it, putting some sequence of other characters, then eval'ing the character ].

Calculating 2+2 using only '(~

CJam, 3 characters

Removed ) as per Martin Ender's suggestion

'(~ 

Similar to the Python one given as an example.

Using '~ you can obtain the ~ character. Then using (, you can decrement it in order to get whatever character you want (~ is the last printable ASCII character). ~ evals any string as normal CJam code. Strings can be constructed by obtaining the character [ (through decrementing ~), eval'ing it, putting some sequence of other characters, then eval'ing the character ]. Through this, you can build and execute any CJam program using only these three characters.

Calculating 2+2 using only '(~

CJam, 3 characters

'(~ 

Similar to the Python one given as an example.

Using '~ you can obtain the ~ character. Then using (, you can decrement it in order to get whatever character you want (~ is the last printable ASCII character). ~ evals any string as normal CJam code. Strings can be constructed by obtaining the character [ (through decrementing ~), eval'ing it, putting some sequence of other characters, then eval'ing the character ].

CJam, 3 characters

Removed ) as per Martin Ender's suggestion

'(~ 

Similar to the Python one given as an example.

Using '~ you can obtain the ~ character. Then using (, you can decrement it in order to get whatever character you want (~ is the last printable ASCII character). ~ evals any string as normal CJam code. Strings can be constructed by obtaining the character [ (through decrementing ~), eval'ing it, putting some sequence of other characters, then eval'ing the character ].

Calculating 2+2 using only '(~

CJam, 4 characters

'()~ 

Similar to the Python one given as an example.

Using ' you can make the character literals of any of these 4 characters. Then using ( and ), it's possible to increment and decrement them in order to get whatever character you want. ~ evals any string as normal CJam code. Strings can be constructed by obtaining the character [ (through increments/decrements), eval'ing it, putting some sequence of other characters, then eval'ing the character ].

CJam, 3 characters

'(~ 

Similar to the Python one given as an example.

Using '~ you can obtain the ~ character. Then using (, you can decrement it in order to get whatever character you want (~ is the last printable ASCII character). ~ evals any string as normal CJam code. Strings can be constructed by obtaining the character [ (through decrementing ~), eval'ing it, putting some sequence of other characters, then eval'ing the character ].