add a field to an object conditionally in javascript

To add a field to an object conditionally, you can use a conditional statement, such as an if statement or a ternary operator, to determine whether the field should be added. To add the field, you can assign a value to a new property on the object using the dot notation or bracket notation.

Here's an example using an if statement:

index.tsx
const myObj = { name: "Alice" };
const shouldAddAge = true;

if (shouldAddAge) {
  myObj.age = 30;
}

console.log(myObj); // { name: "Alice", age: 30 }
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In this example, we have an object myObj with a name property. We want to conditionally add an age property based on the value of the shouldAddAge variable. If shouldAddAge is true, we add the age property to myObj with a value of 30. Finally, we log the updated myObj to the console.

You can also use the spread operator to conditionally add a property to an object. Here's an example using a ternary operator:

index.tsx
const myObj = { name: "Bob" };
const shouldAddAge = false;
const newObject = shouldAddAge ? ({ ...myObj, age: 25 }) : myObj;

console.log(newObject); // { name: "Bob" }
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In this example, we have an object myObj with a name property. We want to conditionally add an age property based on the value of the shouldAddAge variable. We declare a new object newObject and use a ternary operator to check if shouldAddAge is true. If it is, we spread myObj into newObject and also add a new property age with a value of 25. If shouldAddAge is false, we assign myObj to newObject directly. Finally, we log the updated newObject to the console.