Is it possible to change length of arrow?

Question

every join/.style = arrow,
 arrow/.style = {very thick,-stealth}
] 

I am new in tikz(tikzpicture) library, so how can I do this arrow shorter?

Answer 1

Since you showed a piece of code with every join, I suppose you're drawing a chain.

I also suppose you would like to shorten the arrow, not the arrow tip.

If what I suppose is true, you can use shorten >=... to shorten the arrow end and shorten <=..., to shorten the arrow start.

\documentclass[border=.1cm]{standalone}
\usepackage{tikz}
\usetikzlibrary{chains}
\begin{document}
\begin{tikzpicture}[%
  every node/.style={draw, on chain, join},
  start chain=going right,
  every join/.style ={arrow},
  arrow/.style = {very thick, -stealth, shorten >=.2cm,  shorten <=.2cm}
]
\node {A};
\node {B};
\node {C};
\end{tikzpicture}
\end{document}