Shallow object equality in JavaScript

Compares objects one level deep, which is what a re-render check needs.

function shallowEqual(a, b) {
  if (Object.is(a, b)) return true;
  const keysA = Object.keys(a);
  const keysB = Object.keys(b);
  if (keysA.length !== keysB.length) return false;
  return keysA.every((key) => Object.is(a[key], b[key]));
}

Keywords and builtins used here

• Object
• const
• function
• if
• return

The run, in numbers

Lines

7

Characters to type

230

Tokens

81

Three-star pace

95 tpm

At the three-star pace of 95 tokens a minute, this run takes about 51 seconds.

Type this snippet

Step 7 of 8 in Objects & collections, step 33 of 43 in Language basics.

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