Compare two objects JS

Compare two data objects .md

Compare two data objects / arrays in javascript and/or typescript regardless of the order of the data;

When to use:

• When you need compare two "json" objects to know if it have same data.
• When the order of the array doesn't matters ie. [1,2] should be equal [2,1], but it is configurable.
• lightweight - just one small .js file

when not to use:

• when you need to compare more complex objects, with functions, for example.
• when you need a list with all differences between the two objects

expected results:

param 1	param 2	isEqual
{ a: 1, b: 2 }	{ a: 1, b: 2 }	true
{ a: 1, b: 2 }	{ b: 2, a: 1 }	true
{ a: 1, b: 3 }	{ b: 2, a: 1 }	false

param 1	param 2	isEqual
[1, 2]	[1, 2]	true
[1, 2]	[2, 1]	true
[1, 2]	[3, 4]	false

but with checkDataOrder , the order of arrays matters:

checkDataOrder	param 1	param 2	isEqual
false (default)	[1, 2]	[2, 1]	true
true	[1, 2]	[2, 1]	false
false (default)	{ a: [3, 1, 2], b: 2 }	{ b: 2, a: [1, 2, 3] }	true
true	{ a: [3, 1, 2], b: 2 }	{ b: 2, a: [1, 2, 3] }	false

  /////////////////////////////////
  // whith checkDataOrder = false (default value is false)
  console.log(isEqual(null, 12)); //false
  console.log(isEqual(undefined, NaN)); //false
  console.log(isEqual(undefined, undefined)); //true
  console.log(isEqual(undefined, null)); //false
  console.log(isEqual(null, null)); //true
  console.log(isEqual(BigInt("1"), 1)); //false
  console.log(isEqual(Number(1), 1)); // true
  console.log(isEqual({ a: 1, b: 2 }, { b: 2, a: 1 })); // true
  console.log(isEqual({ a: [3, 1, 2], b: 2 }, { b: 2, a: [1, 2, 3] })); // true
  console.log(isEqual([1, 2], [1, 2])); // true
  /////////////////////////////////
  // whith checkDataOrder = true
  console.log(isEqual({ a: 1, b: 2 }, { b: 2, a: 1 }, true)); //  expected result true
  console.log(isEqual([1, 2], [2, 1], true)); // expected result false
  console.log(isEqual({ a: [3, 1, 2], b: 2 }, { b: 2, a: [1, 2, 3] }, true)); // expected result false

isEqual.js

/**
 * @license
 * This code is licensed under the terms of the MIT license
 *
 * Copyright (c) 2022 Marco Antonio Anastacio Cintra <[email protected]>
 * and contributors: 
 * "@bayerlse" - Sebastian Bayerl
 * "@jrson83" -
 * "@bsor-dev"
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

/**
 * Compare two data objects / arrays in javascript.
 *
 * @author Marco Antonio Anastacio Cintra
 * @link https://gist.github.com/anastaciocintra/6a9bf013d8bd940f857d5c9ad08990e1
 * @param {any} obj1 the first object.
 * @param {any} obj2 the second object.
 * @param {boolean} checkDataOrder determine if order  data is relevant on comparison
 *
 * @returns {boolean} return true if obj1 and obj2 have the same data
 *
 * @example
 *
 * expected results:
 * { a: 1, b: 2 } === { a: 1, b: 2 }
 * { a: 1, b: 2 } === { b: 2, a: 1 }
 * { a: 1, b: 3 } !== { b: 2, a: 1 }
 * [1, 2] === [1, 2]
 * [2, 1] === [1, 2]
 * [1, 3] !== [1, 2]
 *
 * but with checkDataOrder = true, the results are different for arrays:
 * [1, 2] === [1, 2] // same result as without checkDataOrder
 * [2, 1] !== [1, 2] // different order
 * [1, 3] !== [1, 2] // same result as without checkDataOrder
 *
 */
export const isEqual = (obj1, obj2, checkDataOrder = false) => {
  const checkDataOrderParanoic = false;
  if (obj1 === null || obj2 === null) {
    return obj1 === obj2;
  }
  let _obj1 = obj1;
  let _obj2 = obj2;
  if (!checkDataOrder) {
    if (obj1 instanceof Array) {
      _obj1 = [...obj1].sort();
    }
    if (obj2 instanceof Array) {
      _obj2 = [...obj2].sort();
    }
  }
  if (typeof _obj1 !== "object" || typeof _obj2 !== "object") {
    return _obj1 === _obj2;
  }

  const obj1Props = Object.getOwnPropertyNames(_obj1);
  const obj2Props = Object.getOwnPropertyNames(_obj2);
  if (obj1Props.length !== obj2Props.length) {
    return false;
  }

  if (checkDataOrderParanoic && checkDataOrder) {
    // whill result in {a:1, b:2} !== {b:2, a:1}
    // its not normal, but if you want this behavior, set checkDataOrderParanoic = true
    const propOrder = obj1Props.toString() === obj2Props.toString();
    if (!propOrder) {
      return false;
    }
  }

  for (const prop of obj1Props) {
    const val1 = _obj1[prop];
    const val2 = _obj2[prop];

    if (typeof val1 === "object" && typeof val2 === "object") {
      if (isEqual(val1, val2, checkDataOrder)) {
        continue;
      } else {
        return false;
      }
    }
    if (val1 !== val2) {
      return false;
    }
  }
  return true;
};

isEqual.ts

/**
 * @license
 * This code is licensed under the terms of the MIT license
 *
 * Copyright (c) 2022 Marco Antonio Anastacio Cintra <[email protected]>
 * and contributors: 
 * "@bayerlse" - Sebastian Bayerl
 * "@jrson83" -
 * "@bsor-dev"
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

/**
 * Compare two data objects / arrays in typescript.
 *
 * @author Marco Antonio Anastacio Cintra
 * @link https://gist.github.com/anastaciocintra/6a9bf013d8bd940f857d5c9ad08990e1
 * @param {any} obj1 the first object.
 * @param {any} obj2 the second object.
 * @param {boolean} checkDataOrder determine if order  data is relevant on comparison
 *
 * @returns {boolean} return true if obj1 and obj2 have the same data
 *
 * @example
 *
 * expected results:
 * { a: 1, b: 2 } === { a: 1, b: 2 }
 * { a: 1, b: 2 } === { b: 2, a: 1 }
 * { a: 1, b: 3 } !== { b: 2, a: 1 }
 * [1, 2] === [1, 2]
 * [2, 1] === [1, 2]
 * [1, 3] !== [1, 2]
 *
 * but with checkDataOrder = true, the results are different for arrays:
 * [1, 2] === [1, 2] // same result as without checkDataOrder
 * [2, 1] !== [1, 2] // different order
 * [1, 3] !== [1, 2] // same result as without checkDataOrder
 *
 */
export const isEqual = (obj1: any, obj2: any, checkDataOrder: boolean = false): boolean => {
  const checkDataOrderParanoic = false;
  if (obj1 === null || obj2 === null) {
    return obj1 === obj2;
  }
  let _obj1 = obj1;
  let _obj2 = obj2;
  if (!checkDataOrder) {
    if (obj1 instanceof Array) {
      _obj1 = [...obj1].sort();
    }
    if (obj2 instanceof Array) {
      _obj2 = [...obj2].sort();
    }
  }
  if (typeof _obj1 !== "object" || typeof _obj2 !== "object") {
    return _obj1 === _obj2;
  }

  const obj1Props = Object.getOwnPropertyNames(_obj1);
  const obj2Props = Object.getOwnPropertyNames(_obj2);
  if (obj1Props.length !== obj2Props.length) {
    return false;
  }

  if (checkDataOrderParanoic && checkDataOrder) {
    // whill result in {a:1, b:2} !== {b:2, a:1}
    // its not normal, but if you want this behavior, set checkDataOrderParanoic = true
    const propOrder = obj1Props.toString() === obj2Props.toString();
    if (!propOrder) {
      return false;
    }
  }

  for (const prop of obj1Props) {
    const val1 = _obj1[prop];
    const val2 = _obj2[prop];

    if (typeof val1 === "object" && typeof val2 === "object") {
      if (isEqual(val1, val2, checkDataOrder)) {
        continue;
      } else {
        return false;
      }
    }
    if (val1 !== val2) {
      return false;
    }
  }
  return true;
};

Thanks, is this MIT license?

hi @jrson83,
I never thought about it, but yeap you can use it for free, I did a little research about licensing gists, and put a @license at top of document.
I don't know if it's the best way, if you know a better way to do this let me know.
see you.

hi @jrson83, I never thought about it, but yeap you can use it for free, I did a little research about licensing gists, and put a @license at top of document. I don't know if it's the best way, if you know a better way to do this let me know. see you.

Cool, thanks. Guess this is totally fine!

Do we have typescript version available

Do we have typescript version available

I tried to type the objects as unknown, but when bundling with microbundle I couldn't get around the error:

export default function isEqual(obj1: unknown, obj2: unknown, checkDataOrder = false): boolean {
  // semantic error TS2571: Object is of type 'unknown

  // ...

 for (const prop of obj1Props) {
    const val1 = obj1![prop as keyof typeof obj1]
    const val2 = obj2![prop as keyof typeof obj2]

    // ...
  }
}

I replaced unknown with any to be able to bundle. If someone has a better solution would be great,

yeap, just change this line:
export const isEqual = (obj1: any, obj2: any, checkDataOrder: boolean = false) => {
I'm adding another file for using with typescript ...

yeap, just change this line: export const isEqual = (obj1: any, obj2: any, checkDataOrder: boolean = false) => { I'm adding another file for using with typescript ...

my mistake, missing boolean return.
export const isEqual = (obj1: any, obj2: any, checkDataOrder: boolean = false): boolean => {

or, simply copy new isEqual.ts file
any problem, let me know.

about my test environment:
react 18 with typescript;
my version of typescript is 4.8.4
my tsconfig.json:

{
  "compilerOptions": {
    "target": "es5",
    "lib": [
      "dom",
      "dom.iterable",
      "esnext"
    ],
    "allowJs": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "noFallthroughCasesInSwitch": true,
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "react-jsx"
  },
  "include": [
    "src"
  ]
}

Do we have typescript version available

I tried to type the objects as unknown, but when bundling with microbundle I couldn't get around the error:

export default function isEqual(obj1: unknown, obj2: unknown, checkDataOrder = false): boolean {
  // semantic error TS2571: Object is of type 'unknown

  // ...

 for (const prop of obj1Props) {
    const val1 = obj1![prop as keyof typeof obj1]
    const val2 = obj2![prop as keyof typeof obj2]

    // ...
  }
}

I replaced unknown with any to be able to bundle. If someone has a better solution would be great,

great!
any works fine for me

Hey there, nice function! Just wanted to tell, that maybe sort shouldn't be used on the original parameter, as its destructive.

So better do:

if (obj1 instanceof Array) {
    _obj1 = [...obj1].sort();
}
if (obj2 instanceof Array) {
    _obj2 = [...obj2].sort();
}

great job @bayerlse,
corrections was made!
I changed in three points:

if (obj1 instanceof Array) {
    _obj1 = [...obj1].sort();
}
if (obj2 instanceof Array) {
    _obj2 = [...obj2].sort();
}

and (lines 93 and 94...)

 for (const prop of obj1Props) {
   const val1 = _obj1[prop];
   const val2 = _obj2[prop];

and in Contributors (MIT license)

Thanks!