6. If statement handling errors

I saw you say something. Let's take a look. Program CodeRight.

If (CH> = '0' & Ch <= '9 '){
/* Process the code normally */
} Else {
/* Output error message */
Printf ("error.../N ");
Return (false );
}

This structure is very bad, especially if the "normal code processing" is very long, it is best not to use else in this case. First Judge the error, such:

If (CH <'0' | ch> '9 '){
/* Output error message */
Printf ("error.../N ");
Return (false );
}

/* Process the code normally */
......

Isn't this structure clear? Highlight the wrong conditions so that when others use your function, they can see invalid conditions at first glance, so they will be more subconsciously avoided.