Tilted Forum Project Discussion Community  

Go Back   Tilted Forum Project Discussion Community > Interests > Tilted Technology


 
 
LinkBack Thread Tools
Old 11-14-2004, 02:17 PM   #1 (permalink)
Junkie
 
Location: Montreal
Total beginner Java questions...

I've just started learning Java this week. Feel free to laugh, I can take it.

So, I'm doing this 9x multiplication table, as an exercise:

class table9x9
{
public static void main(String args[])
{
for(int x = 1; x <= 9; x ++)
{ System.out.print(x + "\t");
for(int y = 2; y <= 9; y ++)
{
System.out.print(x * y + "\t");
}
System.out.println();
}
}
}


Questions... 1) Is this the most elegant way to achieve the results? E.g. I'm not sure about initializing y as 2 (although it does the job)...

2) Is it better to initialize x & y outside of the for loops? Or is that irrelevant?

3) When I run this, the single digit "answers", top-left of the table, do not align evenly. I cannot for the life of me understand why not!

4) My dos shell "copy" button: how do I enable that? Y'know, so I can show the result.

Any help would be appreciated. I've gotta lot of learning to do. Thanks!
crackpot is offline  
Old 11-14-2004, 05:37 PM   #2 (permalink)
Insane
 
Location: Wales, UK, Europe, Earth, Milky Way, Universe
Your solution looks pretty good. I'll help you along with a few pointers. Please note i may not include some criticisms regarding object oriented design etc. because its probably not important to you right now.

Firstly, here's how i would've done it (its rather like yours)
Code:
public class Table9x9 { // Good practice: begin class names with a capital letter

    public static void main(String args[]) {

        for(int x = 1; x <= 9; x++) {
            System.out.print(x + "\t");

            for(int y = 2; y <= 9; y++) {
                System.out.print(x * y + "\t");
            }

            System.out.println();
        }
    }
}
You've probably noticed that i use different "{" placement to you. This is a matter of personal preference.

To answer your questions:

1. Almost elegant enough for me. Check your indentations for logical structure. Whether you initialise x with 1 or 2 is entirely up to you and your project spec.

2. For loops were designed to allow you to initialise variables in the opening statement. This is generally the best way to use a for loop (as you have in your code)

3. This works fine for me, although the single digits do align above the "10's" colum of the next line, but thats irrelevant in this case i think. Maybe it's the font that your command line uses or the width of your window.

4. In my command window, you can right-click and select "mark" which lets you then hilight the text you want to copy. After you hilight, right-click again and it should copy to the clipboard so you can paste into your text editor.

If you're just starting out in java, make sure you get into the habit of commenting your code. Even if it's a small program like this, its best to do it anyway just to get the habit. My code lacked commenting for brevity. Again, i also didnt want to confuse things by mentioning strict object oriented methods. These things you'll learn as you get on

Cue the other programmers with their own personal preferences...
__________________
There are only two industries that refer to their customers as "users". - Edward Tufte
welshbyte is offline  
Old 11-15-2004, 01:38 PM   #3 (permalink)
Crazy
 
Initializing the variables in the for statement gives the variables a bit different scope. If you define the variable in the for statement, the variable will only be accessible in the loop.

You normally don't need your loop counter value to be used outside the loop (there might be the odd case where this might make sense).

In most cases, yes, it will be better to keep variable initialization in the for statement. It will keep your code nice and readable.
scott_p_1 is offline  
Old 11-18-2004, 12:24 AM   #4 (permalink)
Junkie
 
Location: Montreal
Thanks for your insight, welsh & scott. You are both very kind to take the time.
At the risk of sounding even more dweebish, this learning shit is pretty exciting.
Much obliged!
crackpot is offline  
 

Tags
beginner, java, questions, total

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 03:23 AM.

Tilted Forum Project

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
© 2002-2012 Tilted Forum Project

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360