What does it mean 'Legacy octal literals are not allowed in strict mode in react js'?

Question

I am facing an error that shows legacy octal literals are not allowed while working on context API in react. For reference, I am attaching a code snippet below.

const [mission, setMission] = useState({ name: "go to russia", agent: 007, accept: "Not accepted", })

Answer 1

A number starting with a 0 is treated as an octal instead of a decimal.

const value = 010;
console.log(value);

This can be confusing so it has been forbidden in your circumstance.

007 is the same as 7 anyway. If the leading-zero formatting is important then use a string instead (either there where you have 007 or you can use 7 there and format the number on output).

const data = { agent: "007" };
console.log(data.agent);

const format = {
  minimumIntegerDigits: 3,
  minimumFractionDigits: 0,
  useGrouping: false
};
const data = {
  agent: 7
};
console.log(data.agent.toLocaleString('en', format));

Which you use will depend on if you ever need to treat agent as a number or not.