JAVA - what is the difference between void and boolean methods? -


i new java. writing wrapper-library in java make functions available in basic-like language.

i got stock @ point when noted code not executed in java-library although compiler did not complain (using eclipse). resolved replacing code follows:

public void videoquality(int vquality) //did not work

into 

public boolean videoquality(int vquality) //works

here complete code-snippets:

 public void videoquality(int vquality) //did not work {if (vquality==16) { vidquality=16; } else if (vquality==-16) { vidquality=-16; } else if (vquality==0) { vidquality=0; } else vidquality=-16; vitamioext.setvideoquality(vidquality); } public boolean videoquality(int vquality) //works {if (vquality==16) { vidquality=16; } else if (vquality==-16) { vidquality=-16; } else if (vquality==0) { vidquality=0; } else vidquality=-16; vitamioext.setvideoquality(vidquality); return true; }

i think void corresponds sub in visual basic while boolean corresponds function.

i found odd following code worked using void

public void setvolume(float leftvolume,float rightvolume) { vitamioext.setvolume(leftvolume, rightvolume); }

i surely missing obvious can't see why void-code not work while boolean-code worked.

maybe depends how call code?

anyone can shed lights?

edit: clarify not working, meant code:

vitamioext.setvideoquality(vidquality);

did not execute in void-snippet.

edit2: vidquality declared in different part of code. posted snippets since problems , variables functioning.

edit3: @ end, guess must have called void-snippet erroneously although compiler did not compile. in either case, both snippets should execute although of course void-snippet right 1 use since did not expect return-value.

the difference between

public void videoquality(int vquality)

and

public boolean videoquality(int vquality)

is former doesn't return value, , latter (specifically, boolean value). that's full extent of difference.

that means, instance, void version of videoquality:

boolean x = videoquality(10); // not compile videoquality(10); // compile

...because can't assign result of void function variable.

if used boolean version of videoquality:

boolean x = videoquality(10); // compile videoquality(10); // compile

...because although can assign result of function returns boolean boolean variable, don't have to. can ignore return value if like. (usually that's not practice, it's okay.)

i think void corresponds sub in visual basic while boolean corresponds function.

loosely speaking, yes. void indicates function has no return value, sub in vb. else (boolean, int, foo, whatever) indicates a) function has return value, , b) of given type. that's function in vb.


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