Meaning
Parametersareanoptionthatcanbeusedinmanymechanicalsettingsormaintenance.Literally,theyaredataforreference,butsometimestheyarenotalldata.Foragivenapplication,itcanbeaconstantvalueassigned;ingeneral,itcanbeavariableusedtocontrolotherquantitiesthatchangewithitschange.Simplyput,theparametersareforourreference.
Ageneralnumericalmeasurementdescribingtheoverallcharacteristics,whichisacertaincharacteristicvalueofthepopulationthattheresearcherwantstoknow.Theoverallunknownindicatorsarecalledparameters.
Mathematics
Theideaofparameterisimplementedinanalyticgeometry.Forgeometricvariables,peopleusealgebraicexpressionscontainingletterstorepresentvariables.Thisalgebraicexpressioniscalledaparametricexpression,andthelettersarecalledparameters.Usethegeometricpropertiesoffiguresandalgebraicrelationstoconnectintegralexpressionstosolveproblems.Atthesametime,"parametermethod"isalsothesourceofmanyproblem-solvingskills.
Parametricequation
Inagivenplanerectangularcoordinatesystem,ifthecoordinatesxandyofanypointonthecurvearefunctionsofacertainvariabletx=f(t),Y=φ(t),⑴andforeachallowablevalueoft,thepointm(x,y)determinedbytheequationgroup⑴isonthiscurve,thentheequationgroup⑴iscalledtheparameterofthiscurveEquations,thevariablesthatconnecttherelationshipbetweenxandyarecalledparametricvariables,orparametersforshort.
Similarly,therearealsothepolarcoordinateparameterequationsofthecurveρ=f(t),θ=g(t);
Thecircleparameterequationx=a+rcosθ,y=b+rsinθ;(a,b)arethecoordinatesofthecenterofthecircle,ristheradiusofthecircle,andθistheparameter;
Theparametricequationoftheellipsex=acosθ,y=bsinθ,aisthesemi-majoraxisLong,bistheshortsemi-axislength,θistheparameter;
Theparametricequationofthehyperbolax=asecθ(secant),y=btanθ,aistherealsemi-axislength,bistheimaginaryhalfAxislength,θisaparameter;
parabolicequationx=2pt^2,y=2pt,prepresentsthedistancefromthefocustothedirectrix,tisaparameter;
parametersofastraightlineTheequationsx=x'+tcosa,y=y'+tsina,x',y'andaindicatethatthestraightlinepassesthrough(x',y'),andtheinclinationangleisa,andtistheparameter.
SoftRoadQuotations
Theexplanationof"variableparameters"insoftwaredevelopmentisasfollows:
VariableparametersrefertomethodsThenumberofparameterscanbechanged.
Programminglanguage
Java
JDK1.5addsvariable-lengthmethodparameters,thatis,inthemethoddeclarationheader,thenumberofformalparametersisVariable.
Thevariable-lengthformalparameterdeclarationformatisasfollows:
dataType...parameters
Amongthem,theellipsismeansthatthenumberofparameterswhosedatatypeisdataTypeisnotFixed,canbeanynumber.
Whenthemethodiscalled,thevariablelengthparametercanbereplacedwithone,twoormoreparameters.
Forexample,themethodofdeclaringvariable-lengthparametersisasfollows:
voidmymethod(Strings,int...numbers)
ThecallformofthemethodcanbeItisintheformofmymethod("abc",1),mymethod("abcd",1,2)ormymethod("hij",1,2,3).
Atcompiletime,thevariable-lengthparametersofthemethodwillbetreatedasone-dimensionalarraysofthesametype.
Note:Variable-lengthparametershavesomerestrictions:onlyonevariable-lengthparametercanbedefinedinamethod,anditmustbethelastparameterofthemethod.
VB
ThevariableinVBcanbeavariantornotwrittenthatdoesnotbelongtoanytypebutdoesnotbelongtoanytypewillbecomethedefaultvalue
privatesubdemo(byvalaasvariant)
endsub
whereaistheparameterbecausehedidnotsetthedefaultvalue,sofillintheparameterwhencalling
C#
privatestringdemo(stringa)
TheformatinC#whichissimilartojavaisrange+static+returntype+keyword(type+parametername)
adoesnotsetthedefaultvalue,soheneedstofillintheparameterswhencalling
C#iscasesensitive
Theparameterscanbeanytype