How jquery populates data into form fields before updating data

$ ("#p_city option[value= ' ${project.city} ']"). attr ("Selected", "Selected");$("#p_projectType option[value= ' ${project.projecttype} ']"). attr ("Selected", "Selected");$("#p_voltageLevels option[value= ' ${project.voltagelevels} ']"). attr ("Selected", "Selected");$("#p_successfulSupervisionUnits option[value= ' ${project.successfulsupervisionunits} ']"). attr ("Selected", " Selected);$("#currentProgress option[value= ' ${project.currentprogress} ']"). attr ("Selected", "Selected"); $("Input[name= ' project.whetherexcellence '][value= ' ${project.whetherexcellence} '"). attr ("Checked",true);$("Input[name= ' project.whethercreatingmobilered '][value= ' ${project.whethercreatingmobilered} '"). attr ("Checked",true);$("Input[name= ' project.whetherdemonstrationproject '][value= ' ${project.whetherdemonstrationproject} ']". attr (" Checked ",true);$("Input[name= ' project.peaksummerproject '][value= ' ${project.peaksummerproject} '"). attr ("Checked",true);$("Input[name= ' project.whethercontracttermination '][value= ' ${project.whethercontracttermination} ']". attr (" Checked ",true);$("Input[name= ' project.threerisk '][value= ' ${project.threerisk} '"). attr ("Checked",true);$("Input[name= ' project.fourrisk '][value= ' ${project.fourrisk} '"). attr ("Checked",true); $("#planStart"). DatePicker (); $ ("#planEnd"). DatePicker (); $ ("#actualStart"). DatePicker (); $ ("#completedProfileDeliverDate"). DatePicker (); $ ("#contractStartTime"). DatePicker (); $ ("#provincialCompanyStartTime"). DatePicker (); $ ("#controlnd"). DatePicker (); $ ("#controlStart"). DatePicker ();

How jquery populates data into form fields before updating data