The two types of people answering on StackOverflow

[text] Question How to round 2 decimal .. FoAT malFrazon fnston 3 2 2GuEpRa 2 nandls exponent noiton 55 wel. had crgnsly e S el ot . Iaces In lav cr e 9 o Ifthe value is a text type parseFloat123.456. toFixed2 If the value is a number var numb 123.23454 numb numb. toFixed2 17 72272020 1 it 3houd b i hare that the goal o these eflorts s not o compisely iminate tne narent rounding eros caused by the floating point daa ype 3 it il never b2 PSS wihout SHEnng 0 3 Gavs s it ol i 18 Vel S5 3 ase10 Gecimal. Toe o ety oot PG B o o can perform matnemateal opers. producing the bug. The moment your value s the absolte adge where simply nvoking e valua wouid cause JS o poduce the bug. itner before or after youve maripulate i ieres nothing more you could do o alevate that. For axampl you nstantate the vlus 0.014369592998999089 JS wil mmedisely reund 1o 0015 Therafore i you passed that value o any o tese funcions you are actually passing 0.015. At that poin you couleven convert o sing frstand then manipulte . the value wod have o e instantited 25 2 sting fom he star for nat o work. The gosl and oy reasonable expactaton o any funstions crestea o Slevists s 5ug i Smply o Slow for manemata. aperatons to be performed on foating paint values whie pushing he bug allthe way out o he e whare ather e starting value o resting value would produce he bug simpy by beng invoked anyway. Tne only other alematie sclutons would e 0 store e whoe numbers and Gecimal values ndependentl both 2 infegers 5o tha ey are oly eve invoked 35 sueh o fo vy stor i vaiue 55 3 sirng 2nd use 3 comEnaton of Sing MaNRURton 2nd ntege bssad math o perorm operatns on . Afer runing trough varous teraions of 3l he possibie ways o scheve tue accurate decimal ounding precision. s clear that e most accurate and eficent soluon s 0 e Number EPSILON. Tris provices 3 tus matnematies oiton o the prtlem of fosing pant math precizon. can be asly palyiles 5 shoun here s e yeioger mosia cren USidonsWeblJsvaS criptRefersncaGlobal ObjectsNumberEPSILON t support al o the last remaiing IE uses han again maybe w should top daing that. Adapted om the soluton provided here htosstackoverow coma4535004418010362 A simple arop in soluion it provises acourate decimal rounding fooring and csiing with an omtons resisan varisbie winout sading whole rar. 05.18.2020 UPDATE As Sargey noted i the comments thae s mitsfon o s or 3ay Mt that worh poning ot In e Gase of umisrs ke 0.0149999909S9SRS9E 2 il 2 exparience nacouracies which are he resutof ing the absolte edge of sccuracy miations for festing pant vaiue storage. There 7o math or iner sautien ths 220 o8 2palied o sccourt for that 25 the value el immediataly evaluated 33 0.015. You 6an confim his by simply invoking nst valu by 5af n the console. Dus o ths miaton ould ot 4en 52 poss e o use g maripuiaton t raduce s value 35 s sting representaton s simply 0.015 Any soution o Sszunt for this would nesd fo b 3pples logcaly 3 ne source of the o before sver ass2ping the value nto a scrpt. e restioing i characierlengt of a feld ic. Tat woud bea consicaraton hat woula nsad f2 b tken i Scesunt on 3 S5se oy 2558 basi o ceterming e bast spprosen 05.10.2020 UPDATE Per Amrs commentthe cail and foor fnctons wil produce undesied et when the input value an intege. Ti 5 due 0 the addion applisd o the nput with Number EPSILON in rder o ofset ine expectad ioatinacouracy.The function has been updated o check e input value s an nteger and retur the vaue unchanged 35t he carrectresut of stner function when appid fo whol umber Note Tis 208 320 revess hat i e ol 2nd for unations sl raquire he sapicatn of the Number EPSILON adusiment iney do produce undesiable fesus when sppied 0 3 value whara the number of decimals i the input number s lower nan the number of decmas requested for the outpu . For example 171 snoud retum 17.1 in raaton o expected oei functon benaviorwhan applied 0 whale numbers in mathematcs where 3 decimal places afer 1are assumed 1o be 0. To coractfor i Ive added an addionaluncion check fodenty the e of e mls n 7 input et i awer than he requested utput decimls 2nd retm the number unchangad ust 25 with whole numbers. vor Deciastprectsion Function 55 mbar. EPSTLON undefined ier GPSTLON Rt pou3 52 3 LeuntersTnteger o unsetined . sTiteger functionvalue Lsriniteuaue 88 Hath loorvalie value 5 3 ths.sshomd unctionn et 1 n.tostring SpLILC . aLength return 552 3 A ehnter taTntegorn his.tshowdn et o2 3 tlep 8 0 187 o return Rt rondn 7 1 01 3 this.cetd functiontn p2