java - Run-time error. Integer convert to string -

-

i creating program returns ordinal form of number (1st, 2nd etc.). when run program runtime error.

i suspecting has converting int string, can't seem find source of problem.

public void run() {         ordinalform(5);     }      private string ordinalform(int num) {         string number = integer.tostring(num);         string correctword ="";         if((number.charat(number.length()-2)=='1'                 && number.charat(number.length()-1)=='1')){             correctword=number+"th";         } else if (number.charat(number.length()-2)=='1'                 && number.charat(number.length()-1)=='2') {             correctword=number+"th";         } else if ((number.charat(number.length()-1)=='1'                 && number.charat(number.length()-1)=='3')) {             correctword=number+"th";         } else if(number.charat(number.length()-1)=='1') {             correctword=number+"st";         } else if(number.charat(number.length()-1)=='2') {             correctword=number+"nd";         } else if(number.charat(number.length()-1)=='3') {             correctword=number+"rd";         } else {             correctword=number+"th";         }         println(correctword);         return correctword;     } }

the error: exception in thread "thread-1" java.lang.stringindexoutofboundsexception: string index out of range: -1 @ java.lang.string.charat(string.java:646) @ stringtraining.ordinalform(stringtraining.java:17) @ stringtraining.run(stringtraining.java:11) @ acm.program.program.runhook(program.java:1568) @ acm.program.program.startrun(program.java:1557) @ acm.program.appletstarter.run(program.java:1895) @ java.lang.thread.run(thread.java:745)

edit:

you calling method number 5 parameter :

ordinalform(5);

the first instruction executes in ordinalform function :

string number = integer.tostring(num);

this converts variable num (equals 5) string. number equal "5". notice number.length() equal 1 now.

next in condition:

if((number.charat(number.length()-2)=='1' && ....) { }

number.length() equal 1 (number == "5"). therefore, number.length() - 2 equal -1. technically, trying is:

if((number.charat( -1 )=='1' && ....) { }

and since there no such thing index -1, stringindexoutofboundsexception thrown, , execution fails.


Comments

Post a Comment

Popular posts from this blog

javascript - Slick Slider width recalculation -

-
i'm trying add slide in panel on slick container css. carousel works except new width not being calculated when space has been added. recalibrate once advance next slide i'd happen each time panel opened or closed. i've tried adding both margin , padding, neither makes difference. ideas? https://jsfiddle.net/mhigley/dpf7mlpl/ html: <button type="button" id="button"><i class="fa fa-arrow-right"></i></button> <aside> <h2>slide in panel</h2> <ol> <li>list item</li> <li>list item</li> <li>list item</li> <li>list item</li> <li>list item</li> </ol> </aside> <main role="main"> <div class="sections"> <section> <article> <h2>first slide</h2> <p>lorem ipsum d...
Read more

jsf - PrimeFaces Datatable - What is f:facet actually doing? -

-
looking through primefaces code in app noticed following line: <f:facet name="header">#{trainsearch.traincount} trains</f:facet> it looks overriding header, makes sense, can explain me in little more detail? what happening line of code? complete code listed below: <p:datatable id = "results" value = "#{trainsearch.trains}" var = "train" rendered="#{not empty trainsearch.trains}" styleclass = "train-search-table horizontal-border"> <f:facet name="header">#{trainsearch.traincount} trains</f:facet> <p:column headertext = "train id"> <p:panelgrid columns="1" styleclass = "train-id-grid" layout = "grid"> <h:outputtext styleclass = "train-id-label" value="#{train.traini}"/> <h:outputtex...
Read more

javascript - Error handling and status codes with knex in koa -

-
i'm experimenting koa , knex build restful web service, , while got basics working i'm stuck @ handling errors. i'm using koa-knex-middleware wraps knex in generator. i have following code defines happens , post requests particular resource: var koa = require('koa'); var koabody = require('koa-body')(); var router = require('koa-router')(); var app = koa(); var knex = require('./koa-knex'); app.use(knex({ client: 'sqlite3', connection: { filename: "./src/server/devdb.sqlite" } })); router .get('/equipment', function *(next){ this.body = yield this.knex('equipment'); }) .post('/equipment', koabody, function *(next){ this.body = yield this.knex('equipment').insert(this.request.body) }); app.use(router.routes()).use(router.allowedmethods()); app.listen(4000); this works in general, can't manage change http status codes. examp...
Read more