how to check conditions inside .then in javascript

July 16, 2022

Existing code(Working fine) :

.then((result) => { 
                this.triggerAction(result.id); 
            }).catch((error) => { 
              this.errorMsg(error);
            });

when i try to add condition inside the .then throws error.

.then((result && result.id) => {
               this.triggerAction(result.id); 
            }).catch((error) => { 
              this.errorMsg(error);
            });

I need to check both result and result.id is coming in the response and throws error id if not available in the result .

>Solution :

To throw an error if result.id is missing, you should do the following:

          .then((result) => {
            if(!result.id) {
               throw new Error("result.id is missing!");
            }
            this.triggerAction(result.id); 
          }).catch((error) => { 
            this.errorMsg(error);
          });

You can also do throw result if you just want to pass result to the .catch() block