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TypeScript

TS102

3

The JavaScript Problem

Many JavaScript mistakes are not discovered until the program actually runs.

What problem does TypeScript solve?

TypeScript finds many programming mistakes before the JavaScript program is executed.

JavaScript usually waits until execution before reporting many errors.

By then the user may already be affected.

TypeScript checks the program while it is being built.

The goal is to discover problems earlier.

Earlier mistakes are usually easier to repair.

Wrong assignment

The variable is declared as a number.

A string is assigned later.

The compiler reports the mismatch.

The mistake is found before deployment.

The programmer fixes the code before users see the problem.

Earlier

Finding mistakes early saves time.

Reliable

Programs become easier to trust.

Maintenance

Large code bases become safer to change.

Teams

Everyone follows the same expectations.

Changing the type

Keeping the type

Ask ChatGPT: "Explain why the compiler rejects this assignment."

Declare a number variable.

Assign another number.

Assign text instead.

Read the compiler error.

Explain what the compiler protected you from.

Ignoring compiler errors.

Assigning the wrong data type.

Thinking JavaScript and TypeScript check values the same way.

Removing types to hide errors.

Testing only after deployment.

Explain how TypeScript catches many JavaScript mistakes before execution.