26 lines
1.3 KiB
Markdown
26 lines
1.3 KiB
Markdown
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Statements
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==========
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{{#include ../links.md}}
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Statements are terminated by semicolons '`;`' and they are mandatory,
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except for the _last_ statement in a _block_ (enclosed by '`{`' .. '`}`' pairs) where it can be omitted.
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A statement can be used anywhere where an expression is expected. These are called, for lack of a more
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creative name, "statement expressions." The _last_ statement of a statement block is _always_ the block's
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return value when used as a statement.
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If the last statement has no return value (e.g. variable definitions, assignments) then it is assumed to be [`()`].
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```rust
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let a = 42; // normal assignment statement
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let a = foo(42); // normal function call statement
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foo < 42; // normal expression as statement
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let a = { 40 + 2 }; // 'a' is set to the value of the statement block, which is the value of the last statement
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// ^ the last statement does not require a terminating semicolon (although it also works with it)
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// ^ semicolon required here to terminate the assignment statement; it is a syntax error without it
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4 * 10 + 2 // a statement which is just one expression; no ending semicolon is OK
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// because it is the last statement of the whole block
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```
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