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The error "No index signature with a parameter of type 'string' was found on type" occurs when we use a value of type string to index an object with specific keys. To solve the error, type the string as one of the object's keys using keyof typeof obj .

A type signature is like a blueprint for any given segment of code. It tells the compiler what things are. Well-typed programs are more reliable and they run faster. They also give the compiler a lot of additional information which helps us identify errors faster.

If you want to create an object type with a fixed set of keys and values, you should use a Record. If you want to create an object type that can have any number of properties, but the values for those properties must have a specific type, you should use an index signature.

An index signature is a way to define the Shape of fields which are not known ahead of time. The [key: string]: number; is the index signature, which indicates to TypeScript that any fields on the object which are not mentioned will be a particular types.

The error "Property is incompatible with index signature" occurs when a property is not compatible with the specified type of the index signature. To solve the error, change the type of the property or use a union to update the type in the index signature.

The idea of the index signatures is to type objects of unknown structure when you only know the key and value types. An index signature fits the case of the salary parameter: the function should accept salary objects of different structures — just make sure that object values are numbers.

The name of the index signature, for example, index in { [index:string]: { message:string}} For example, if it's usernames, you may do { [username:string]: {message:string}} to assist the next developer who will look at the code (which just might happen to be you).

The index signature consists of the index name and its type in square brackets, followed by a colon and the value type: { [indexName: Keys]: Values } . Keys can be a string , number , or symbol , while Values can be any type.

The error "No index signature with a parameter of type 'string' was found on type" occurs when we use a value of type string to index an object with specific keys. To solve the error, type the string as one of the object's keys using keyof typeof obj .

A type signature is like a blueprint for any given segment of code. It tells the compiler what things are. Well-typed programs are more reliable and they run faster. They also give the compiler a lot of additional information which helps us identify errors faster.

If you want to create an object type with a fixed set of keys and values, you should use a Record. If you want to create an object type that can have any number of properties, but the values for those properties must have a specific type, you should use an index signature.

An index signature is a way to define the Shape of fields which are not known ahead of time. The [key: string]: number; is the index signature, which indicates to TypeScript that any fields on the object which are not mentioned will be a particular types.

The error "Property is incompatible with index signature" occurs when a property is not compatible with the specified type of the index signature. To solve the error, change the type of the property or use a union to update the type in the index signature.

The idea of the index signatures is to type objects of unknown structure when you only know the key and value types. An index signature fits the case of the salary parameter: the function should accept salary objects of different structures — just make sure that object values are numbers.

The name of the index signature, for example, index in { [index:string]: { message:string}} For example, if it's usernames, you may do { [username:string]: {message:string}} to assist the next developer who will look at the code (which just might happen to be you).

The index signature consists of the index name and its type in square brackets, followed by a colon and the value type: { [indexName: Keys]: Values } . Keys can be a string , number , or symbol , while Values can be any type.