As operator
The as operator is language syntax that associates a value or expression with a specified type through assertion, casting, or conversion, depending on the language.
Learn Rust in a Month of Lunches
The as operator performs explicit primitive-type conversions in Rust.
- How it is used
- Uses explicit conversion to turn an integer value into a character.
- How deep it goes
- Works through a rejected cast and two corrections, without detailing conversion rules for every primitive type.
- Examples
- Shows `100` rejected as an `i32`-to-`char` cast, then converted through `u8`.
- What you can do after
- Apply it in Rust to correct the illustrated integer-to-character cast.
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Pro Angular 16
A type assertion is TypeScript syntax that tells the compiler to treat an expression as a specified type without changing the runtime value.
- How it is used
- Resolves TypeScript compiler uncertainty in mixed-type addition and array reduction.
- How deep it goes
- Demonstrates two assertion sites and their results, while warning that `any` weakens checking; does not examine compiler internals.
- Examples
- Shows `(param as any) + 100` producing different numeric and string results, and `val as number` in a sum.
- What you can do after
- Apply it via TypeScript’s `as` keyword where inference falls short, while recognizing that an assertion does not validate runtime values.
Rust in Action: Systems programming concepts and techniques
The as operator is Rust syntax for explicitly converting a value to another type using a permitted cast.
- How it is used
- Uses explicit casts to make differently typed numeric values comparable.
- How deep it goes
- Explains syntax, promotion, narrowing risks, and fallible conversion, while deferring full traits and Result treatment.
- Examples
- Uses a mixed-type comparison, a narrowing integer cast, and a try_into conversion listing.
- What you can do after
- Apply explicit numeric casts to resolve compatible comparisons and recognize when fallible conversion is safer.
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Related concepts
- type assertionused by · A type assertion is a language construct that states or checks that a value has a specified type, with runtime behavior depending on the language.
- ClassCastExceptionproduces · ClassCastException is a Java runtime exception thrown when a value cannot be cast to the requested reference type.
- atomic typeuses · An atomic type is a type whose supported accesses and operations are indivisible with respect to concurrent execution and provide defined synchronization semantics.
- data conversionkind of · Data conversion is the transformation of a value or data from one type, format, or representation to another, explicitly or implicitly.
- template literaluses · A JavaScript string literal delimited by backticks that supports multiline text and embedded expressions.
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