{"id":21023,"date":"2022-11-11T19:12:33","date_gmt":"2022-11-11T13:42:33","guid":{"rendered":"https:\/\/jassweb.com\/solved\/solved-try-and-catch-error-with-joptionpane\/"},"modified":"2022-11-11T19:12:33","modified_gmt":"2022-11-11T13:42:33","slug":"solved-try-and-catch-error-with-joptionpane","status":"publish","type":"post","link":"https:\/\/jassweb.com\/solved\/solved-try-and-catch-error-with-joptionpane\/","title":{"rendered":"[Solved] try and catch error with joptionpane"},"content":{"rendered":"

[ad_1]
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The warning (which can be ignored) is telling you that the variable e<\/code> you’ve declared in your catch block is not used. I know with IntelliJ IDEA you can remove the warning by changing the name of e<\/code> to ignored<\/code>. I’m not sure if NetBeans has a similar feature.<\/p>\n

However, your try block is rather pointless. It should be around your Double.parseDouble()<\/code> calls, because those are what will fail if the input from the user was not something that could be interpreted as a number. The only method within your try block that could potentially throw an exception would be z.format(f)<\/code> and only if z<\/code> had its rounding mode set to RoundingMode.UNNECESSARY<\/code> which it isn’t by default.<\/p>\n

Try something more like this.<\/p>\n

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         \n    DecimalFormat z = new DecimalFormat(\"0.00\");\n    try  {\n      double x = Double.parseDouble(fnum.getText());     \n      double y = Double.parseDouble(secondnum.getText());\n      double f = x + y;\n      String number = z.format(f);\n      answer.setText(\"\" + number);\n    } catch(NumberFormatException e) {\n      JOptionPane.showMessageDialog(null, \"please input a valid number\");\n    }\n}\n<\/code><\/pre>\n
Edit: As pointed out in the comments on OP, catching Exception is not generally recommended, so updated to catch the more specific NumberFormatException instead.<\/p>\n<\/p><\/div>\n
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            0<\/span> <\/p><\/div>\n<\/div>\n
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solved try and catch error with joptionpane <\/p>\n","protected":false},"excerpt":{"rendered":"
[ad_1] The warning (which can be ignored) is telling you that the variable e you’ve declared in your catch block is not used. I know with IntelliJ IDEA you can remove the warning by changing the name of e to ignored. I’m not sure if NetBeans has a similar feature. However, your try block is … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[320],"tags":[323],"class_list":["post-21023","post","type-post","status-publish","format-standard","hentry","category-solved","tag-java"],"yoast_head":"\n[Solved] try and catch error with joptionpane - JassWeb<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/jassweb.com\/solved\/solved-try-and-catch-error-with-joptionpane\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[Solved] try and catch error with joptionpane - JassWeb\" \/>\n<meta property=\"og:description\" content=\"[ad_1] The warning (which can be ignored) is telling you that the variable e you’ve declared in your catch block is not used. 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