EC
TS2371
TypeScriptERRORNotableTypeHIGH confidence

A parameter initializer is only allowed in a function or constructor implemen...

Production Risk

Build will fail; resolve before shipping.

What this means

A type-checking error (TS2371): A parameter initializer is only allowed in a function or constructor implementation.. This diagnostic is emitted by the TypeScript compiler when a parameter initializer is only allowed in a function or constructor implementation..

Why it happens
  1. 1The function overload signatures do not match the implementation
How to reproduce

TypeScript compiler reports TS2371 during type checking.

trigger — this will error
trigger — this will error
// Triggers TS2371
// A parameter initializer is only allowed in a function or constructor implementation.

expected output

error TS2371: A parameter initializer is only allowed in a function or constructor implementation.

Fix

Address the TypeScript diagnostic

WHEN When this error is reported by the compiler

Address the TypeScript diagnostic
// Run the TypeScript compiler for details:
npx tsc --noEmit
// Use the TypeScript playground to test your code:
// https://www.typescriptlang.org/play

Why this works

Review the full error message and location; the TypeScript handbook provides guidance on each error category.

Sources
Official documentation ↗

TypeScript Compiler Diagnostics

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