Why Big Tech Bans JavaScript Short‑Circuit Operators and Safer Alternatives

In many large tech companies' JavaScript coding standards, restrictions on the use of short‑circuit operators are common. These seemingly convenient syntactic sugars can become potential threats.

What are short‑circuit operators

In JavaScript, short‑circuit operators mainly refer to

&&

and

||

, which have the "short‑circuit" behavior:

&&

: when the left‑hand expression is falsy, it returns the left value and does not evaluate the right side.

||

: when the left‑hand expression is truthy, it returns the left value and does not evaluate the right side.

Concerns of large companies

1. Code readability issues

Compared to the first code style, the second version is longer but its intent is clearer. In large projects, readability often outweighs brevity.

2. Unexpected type coercion

JavaScript is a weakly typed language; truthy/falsy evaluation in short‑circuit expressions can lead to unexpected results:

3. Maintenance difficulty

When business logic becomes complex, nesting short‑circuit expressions makes code hard to understand and maintain:

<code>const value = obj && obj.prop && obj.prop.subProp && obj.prop.subProp.value || defaultValue;</code>

4. Debugging difficulty

Short‑circuit expressions are hard to set breakpoints on specific nodes during debugging, increasing the difficulty of troubleshooting.

Alternative approaches

Modern JavaScript provides safer and clearer alternatives:

Use the optional‑chaining operator

?.

Use the nullish‑coalescing operator

??

Use a conditional expression

condition ? valueIfTrue : valueIfFalse

Use an explicit

if

statement

Prohibiting or restricting short‑circuit operators is not an arbitrary decision; it is based on long‑term considerations of maintainability, readability, and code quality. While aiming for elegant concise code, readability and maintainability must also be valued.