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of the form \code{\{ expr1 ; expr2 \}}.
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of the form \code{\{ expr1 ; expr2 \}}.
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}
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}
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}
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}
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\details{
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\details{
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\code{break} breaks out of a \code{for}, \code{while} or \code{repeat}
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\code{break} breaks out of a \code{for}, \code{while} or \code{repeat}
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loop, that is goes to the first statement after the loop.
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loop; control is transferred to the first statement outside the inner-most loop.
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\code{next} transfer control to the first statement of the loop (after
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\code{next} halts the processing of the current iteration and advances the
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advancing \code{var} along \code{seq} in a \code{for} loop). They
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looping index. Both \code{break} and \code{next} apply only to the innermost
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both apply only to the innermost of nested loops.
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of nested loops.
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Note that it is a common mistake to forget to put braces (\code{\{ .. \}})
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Note that it is a common mistake to forget to put braces (\code{\{ .. \}})
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around your statements, e.g., after \code{if(..)} or \code{for(....)}.
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around your statements, e.g., after \code{if(..)} or \code{for(....)}.
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In particular, you should not have a newline between \code{\}} and
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In particular, you should not have a newline between \code{\}} and
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\code{else} to avoid a syntax error in entering a \code{if ... else}
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\code{else} to avoid a syntax error in entering a \code{if ... else}
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construct at the keyboard or via \code{source}.
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construct at the keyboard or via \code{source}.
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For that reason, one (somewhat extreme) attitude of defensive programming
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For that reason, one (somewhat extreme) attitude of defensive programming
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uses braces always, e.g., for \code{if} clauses.
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is to always use braces, e.g., for \code{if} clauses.
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The index \code{seq} in a \code{for} loop is evaluated at the start of
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The index \code{seq} in a \code{for} loop is evaluated at the start of
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the loop; changing it subsequently does not affect the loop. The
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the loop; changing it subsequently does not affect the loop. The
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variable \code{var} has the same type as \code{seq}. If \code{seq} is
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variable \code{var} has the same type as \code{seq}. If \code{seq} is
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a factor (which is not strictly allowed) then its internal codes are
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a factor (which is not strictly allowed) then its internal codes are
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