freeCodeCamp/guide/english/certifications/javascript-algorithms-and-data-structures/es6/prevent-object-mutation/index.md

title

title
Prevent Object Mutation

Prevent Object Mutation

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Hints

Hint 1

• Use Object.freeze() to prevent mathematical constants from changing.

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Solutions

Solution 1 (Click to Show/Hide)

function freezeObj() {
  "use strict";
  const MATH_CONSTANTS = {
    PI: 3.14
  };

  Object.freeze(MATH_CONSTANTS);

  try {
    MATH_CONSTANTS.PI = 99;
  } catch (ex) {
    console.log(ex);
  }
  return MATH_CONSTANTS.PI;
}

const PI = freezeObj();

Code Explanation

• By using Object.freeze() on MATH_CONSTANTS we can avoid manipulating it.

Relevant Links

• "Object.freeze()" - MDN Javascript reference