Angular typescript switch case by some values-CodePudding

I just try to make a switch by two values.

switch ({'a': val_a,'b': val_b}){
  case ({'x','y'}):
    "some code here"
    break;
}

and this not working... any help? thanks!

CodePudding user response：

Switch operator only works for primitives, it's not possible to compare objects, but you can create primitive by yourself, e.g string

const compareValue = val_a   ' '   val_b;

switch (compareValue){
  case 'x y':
    //"some code here"
    break;
}

CodePudding user response：

The value in a case statement must be a constant or a literal or an expression that evaluates to a constant or a literal. You can't expect a switch statement to have objects and underyling case statements have their own objects and do a comparison.

Having said that you've options in javascript that allow you to transform an object (just for comparison purpose). An approach I would following would be like this

let obj = {'a': 'x','b': 'y'};
let obj1={a:'x',b:'y'};
switch(Object.values(obj).join(','))
{
 case Object.values(obj1).join(','):
   console.log('evaluation succeeds');
 break;
}

So what I've done is took the object values and joined with a comma(effectively having a string), and in the case statement did same with another object (so that comparison could take place)