java - Is it necessary to resolve the errors shown in the output window of Netbeans IDE even if my code is working the way I want? -

say want 'of' typed in input user

i making app, not finishing off in dumb output screen (this example)

 import java.util.*;  scanner input = new scanner(system.in);  string text = input.nextline();  int check = 0;  for(int = 0; < text.length(); i++;){      if(text.substring(i, + 2) .equals("of")){           check = 0;      }  } 

if user enters abofd, surely recognises of @ position @ 2-4. when i value 4 checks position 4-6, position 6 not present not present gives error. know thinking me set i < text.length() - 1 @ line 5, original code needs run until end!

it good idea validate input coming user, overcomplicating things! worse, wrote down outright wrong code:

string text = input.nextline(); int check = 0; for(int = 0; < text.length(); i++;){    if(text.substring(i, + 2) .equals("of")){ 

the above can't work! see, i iterates 0 text length. using i+2 substring text. (so: hello first arrayindexoutofboundsexception).

instead, can things like:

if (text.contains("of")) { 

or

if (text.indexof("of") >= 0) { 

to find out if string contains "of".

and answer question in title: absolutely yes. programming being craftsman large degree. craftsman keeps tools , materials in order. doesn't allow mess, waste, ...

so, long story short: day one, eternity: when writing code, strive zero tolerance policy: no compiler errors, no warnings, nothing in code doesn't belong there!