ts-r
  • Error
  • Reported by the type checker

TS2365

Operator '{0}' cannot be applied to types '{1}' and '{2}'.

A binary operator is used on two types it doesn't work with, like `+` on a number and an object, or `<` on a number and a string.

What it means

Operators such as +, <, >, <= and >= accept only some combinations of operand types. The message names the operator and both types.

Example

index.ts
const a = 1;
const b = { value: 2 };

export const c = a + b;
ts-r-check -p tsconfig.json --pretty false ts-r output
index.ts(4,18): error TS2365: Operator '+' cannot be applied to types '1' and '{ value: number; }'.

Recorded by node scripts/verify-examples.mjs with ts-r built from commit 6deaf01. The example uses the default tsconfig: strict, target: es2022, module: esnext, moduleResolution: bundler.

How to fix

  • Use the property you meant (a + b.value), or convert the operands so both are numbers (or both strings).