javascript - cannot let another variable point to console.log -

this question has answer here:

• uncaught typeerror: illegal invocation in javascript 2 answers

i new javascript terminologies might wrong. since functions variables in javascript, why chrome console complain when

var f = console.log   

and apply

f(123)   

the error log following.

uncaught typeerror: illegal invocation       @ <anonymous>:2:1       @ object.injectedscript._evaluateon (<anonymous>:905:140)       @ object.injectedscript._evaluateandwrap (<anonymous>:838:34)       @ object.injectedscript.evaluate (<anonymous>:694:21)   

works here: http://jsfiddle.net/8pl5lgd2/

var f = console.log; f("!23");