java - Check which (combinations) of parameters are null -

suppose have 4 variables

string a; string b; string c; string d; 

i want check if individual variable or combination of variable not null , act accordingly.

for example 1 way using if-else way

     if(a!=null && b == null && c == null && d == null) {            //dosomething }      else if(a==null && b!= null && c == null && d == null) {           //dosomething }      else if(a==null && b!= null && c == null && d == null) {           //dosomething }      else if(a==null && b== null && c != null && d == null) {          //dosomething }       ......         //similarly combination of 2 variables      if(a!=null && b != null && c == null && d == null) {          //dosomething }      else if(a!=null && b== null && c != null && d == null) {          //dosomething }      else if(a!=null && b== null && c == null && d != null) {          //dosomething }        ......         //and on          //similarly combination of 3 variables      if(a!=null && b != null && c != null && d == null) {         //dosomething }      else if(a!=null && b== null && c != null && d != null) {         //dosomething }      else if(a!=null && b== null && c == null && d != null) {          //dosomething }         .... 

how achieve kind of situation switch don't accept null thought of using queue dont allow null values need have key variable can value , manipulate something. appreciated

you build additional variable achieve switch statement:

int switchvar = 0;  if (a == null) {switchvar += 1;} if (b == null) {switchvar += 10;} if (c == null) {switchvar += 100;} if (d == null) {switchvar += 1000;} 

and can use

switch (switchvar) {    case(1): //only ==null  ...    case(101): //a == null ,  c == null  ....    case(1011): //a,b,d null   ....    case(1111): // variables null  }