Expression C and C programmers will find that the expression in D is familiar, and there are some interesting to expand.
Expressions are used to calculate multiple values and return a specific type of value. Subsequent values can be used to assign, test, or ignored. Expressions may also have side effects.
expression:
Assignment expression
Assignment expressions, expressions
Assignment expression:
Conditional expression
Conditional expression = assignment expression
Conditional expression = assignment expression
Conditional expression - = assignment expression
Conditional expression * = assignment expression
Conditional expression / = assignment expression
Conditional expression% = assignment expression
Conditional Expression & = Assignment Expression
Conditional expression | = assignment expression
Conditional expression ^ = assignment expression
Conditional expression ~ = assignment expression
Conditional expression << = assignment expression
Conditional expression >> = assignment expression
Conditional expression >>> = assignment expression
Conditional expression:
OROR expression
OROR expression? Expression: conditional expression
OROR expression:
Andand expressions
OROR Expression || Andand Expressions
Andand expressions:
Expression
Andand Expressions && or Expressions
Or expression:
Tone or expressions
Or expression | alone or expression
Tone or expressions:
Expression
Tone or expressions ^ and expressions
And expressions:
Equal expression
Equally expressions with expressions
Equal expression:
Relational expression
Equal expressions == Relationship expression
Equal expressions! = Relational expression
Equal expressions IS relationship expression
Relationship expression:
Displacement expression
Relationship expression Relational expression <= shift expression Relationship expression> Displacement expression Relationship expression> = shift expression Relationship expression! <> = Shift expression Relationship expression! <> Shift expression Relationship expression <> shift expression Relational expression <> = shift expression Relationship expression!> Displacement expression Relationship expression!> = Shift expression Relationship expression! Relationship expression! <= Shift expression Relationship expression in shift expression Displacement expression: Expressive Displacement expression << and expressions Displacement expression >> and expressions Displacement expression >>> and expressions And expressions: Accumulate And expressions volume list And expressions And expressions ~ Complexed: One yuan expressions Complexed by the format * one yuan express Complexed format / one yuan express Complexed by volume% of one yuan express One yuan express: Suffix expression & One dollar expression one yuan expressions - a metal expression * One yuan expressions - a metal expression 1 yuan express ! One yuan expressions ~ One yuan expression DELETE 1 yuan expressions New expression CAST (type) one yuan expressions (Type). Mark (Expression) Suffix expression: Basic expression Suffix expression. Suffix expression Suffix expression - Suffix expression (parameter list) Index expression Sliced expression Index expression: Suffix expression [parameter list] Slice expression: Suffix expression [assignment expression .. assignment expression] Basic expression: Marker Flag THIS Super NULL True False Numerical text Character text Character string Functional volume Assertion expression Basic type. Signature TYPEID (Type) Aspect: askERT (expression) parameter list: Assignment expression Assigning expression, parameter list NEW expression: NEW Basic Type Stars [Assignment Expression] Notes New Basic Type Stars (Parameter List) New Basic Type Stars NEW (Parameter List) Basic Type Stars [Assignment Expression] Disclaimer NEW (parameter list) basic type stars (parameter list) NEW (parameter list) Basic Type Stars Stars Nothing * * Stars EXPRESSION: AssignExpression AssignExpression, Expression AssignExpression: ConditionaLexpression ConditionaLexpression = AssignExpression ConditionaLexpression = AssignExpression ConditionaRexpression - = AssignExpression Conditionales * = AssignExpression Conditionales / = AssignExpression ConditionaRexpression% = AssignExpression ConditionaRexpression & = AssignExpression ConditionaRexpression | = AssignExpression Conditionales ^ = AssignExpression ConditionaLexpression ~ = assignexpression ConditionaRexpression << = AssignExpression ConditionaLexpression >> = assignexpression ConditionaRexpression >>> = AssignExpression ConditionaRexpression: OROREXPRESSION OROREXPIRESSION? Expression: ConditionaRexpression OROREXPRESSION: Andandexpression OroPression || AndandExpression Andandexpression: OREXPRESSION Andandexpression && Orexpression OREXPIRESSION: XOREXPRESSION Orexpression | XOREXPRESSION XOREXPRESSION: AndExpression XOREXPRESSION ^ AndExpression AndExpression: Equalexpression AndExpression & equalExpression Equalexpression: Relexpression Equalexpression == Relevance Equalexpression! = Relevance Equalexpression is Relexpression Relevance: Shiftexpression Relevance Relevance <= shiftExpression Relevance> Shiftexpression Relevance> = shiftExpression Relevance! <> = ShiftexpressionReleXpression! <> ShiftExpression Relevance <> shiftExpression Relevance <> = shiftExpression Relevance!> Shiftexpression Relevance!> = ShiftExpression Relevance! Relevance! <= Shiftexpression Relevance in shiftexpression ShiftExpression: AddExpression Shiftexpression << AddExpression Shiftexpression >> AddExpression Shiftexpression >>> AddExpression AddExpression: MulexPression AddExpression MULEXPRESSION AddExpression - MULEXPRESSION AddExpression ~ MULEXPRESSION MulexPression: UnaryExpression MULEXPRESSION * UnaryExpression MULEXPIESSION / UNARYEXPRESSION MULEXPRESSION% UnaryExpression UnaryExpression: PostfixExpression & UnaryExpression unaryExpression - UnaryExpression * UnaryExpression - UnaryExpression UnaryExpression ! Unaryexpression ~ UnaryExpression Delete UnaryExpression NewExpression Cast (Type) UnaryExpression (TYPE). Identifier (Expression) PostfixExpression: PRIMARYEXPIPRESSION PostfixExpression. Identifier PostfixExpression PostfixExpression - PostfixExpression (argumentlist) Indexexpression SLICEEXPRESSION IndexExpression: PostfixExpression [argumentlist] SLICEEXPISSION: PostfixExpression [assignexpression .. assignexpression] PRIMARYEXPRESSION: Identifier .IDENTIFIER THIS Super NULL True False Numericliteral Characterliteral Stringliteral FunctionLiteral AskSERTEXPRESSION BasicType. Identifier TypeID (Type) AskERTEXPISSION: askERT (Expression) Argumentlist: AssignExpression AssignExpression, ArgumentList NEWEXPRESSION: New BasicType Stars [AssignExpression] DECLARATORNEW BasicType Stars (argumentlist) New BasicType Stars New (argumentlist) BasicType Stars [AssignExpression] DECLARATOR New (argumentlist) BasicType Stars (ArgumentList) NEW (argumentlist) BasicType Stars Stars Nothing * * Stars The order of assessment is unless otherwise specified (such as OR or ANDAL), the implementation of D can be evaluated in any part of the expression in any order. If there is no additional specification, it cannot rely on the order of value. For example, the following code is illegal: i = i; C = a (a = b); FUNC ( i, i); If the compiler can determine the value of the expression is dependent on the order order, it will report an error (but this is not a must). The ability to detect such errors is the quality of the realization. expression Assignment expressions, expressions AssignExpression, Expression First calculate first , 'The number of operands left, then calculate the number of operands on the right. The type of expression is the type of the operand on the right, and the result of the expression is the result of the number of operands on the right. Assignment expression Conditional expression = assignment expression ConditionaLexpression = AssignExpression The type of the right operand will be implicitly converted to the type of left operand and assigns the left to the left. The type of operand is the type of left destined, and the value of the result is the value of the left value after assignment. The left operand must be left value. Assignment operator expression Conditional expression = assignment expression Conditional expression - = assignment expression Conditional expression * = assignment expression Conditional expression / = assignment expression Conditional expression% = assignment expression Conditional Expression & = Assignment Expression Conditional expression | = assignment expression Conditional expression ^ = assignment expression Conditional expression << = assignment expression Conditional expression >> = assignment expression Conditional expression >>> = assignment expression ConditionaLexpression = AssignExpression ConditionaRexpression - = AssignExpression Conditionales * = AssignExpression Conditionales / = AssignExpression ConditionaRexpression% = AssignExpression ConditionaRexpression & = AssignExpression ConditionaRexpression | = AssignExpression Conditionales ^ = AssignExpression ConditionaRexpression << = AssignExpression ConditionaLexpression >> = assignexpression ConditionaRexpression >>> = AssignExpression Assignment operator expressions, such as: A op = B Is equivalent to: a = a op b Differences are operands a only calculates once. Conditional expression OROR expression? Expression: conditional expression OROREXPIRESSION? Expression: ConditionaRexpression The first expression will be converted to a Boolean and is calculated. If the result is true, the second expression is calculated, the resulting result is the result of the conditional expression. If the result is false, the third expression is calculated, the result is the result of the conditional expression. If the second or third expression is a VOID type, the type returned is VOID. Otherwise, the type of the second and third expressions will be implicitly converted to a common type thereof and become the type of conditional expression results. OROR expression OROR Expression || Andand Expressions OroPression || AndandExpression The return type of the OROR expression is a Boolean, and the result is a VOID type when the number of operands is VOID. OROR expression calculates its leftmost operand. If the left operand is transformed into the Boolean type, the result is not true, and the number of operands on the right is not calculated. If the type of OROR expression results are Boolean, the result of the expression is true. If the left operand is false, the number of operands on the right is calculated. If the OROR expression is a Boolean, the result is the result of the operating number of the right side into the Boolean result. Andand expressions Andand Expressions && OR Expressions Andandexpression && Orexpression The return type of the Andand expression is a Boolean. The exception is that when the operand on the right is Void, the result is a VOID type. Andand expressions calculate the number of operands on the left. If the left operand is transformed into the Boolean, the result is not to calculate the number of operands on the right. If the type of Andand expression results are Boolean, the result of the expression is false. If the left operand is true, the number of operands on the right is calculated. If the Andand expression is a Boolean, the result is the result of the operating number of the right side to the Boolean results. Bit-bit expressions are bitten by bit by bit expressions. Their operands must be positive types. First, the default positive number will be applied. Then, perform a bitwise operation. OR expression Or expression | alone or expression Orexpression | XOREXPRESSION Execute 'or' calculations between operands. XOR expression Tone or expressions ^ and expressions XOREXPRESSION ^ AndExpression Execute the 'different or' calculation between operands. And expression Equally expressions with expressions AndExpression & equalExpression Execute 'and' calculations between operands. Equal expression Equal expressions == Relationship expression Equal expressions! = Relational expression Equal expressions IS relationship expression Equalexpression == Relevance Equalexpression! = Relevance Equalexpression is Relexpression Equal expressive compare equality operators ( ==) or unequal operators ( ! =) Two operands. The type of result is a Boolean. Prior to comparison, the operands are transformed into one common type through common conversion transformation. If the operand is an integer value or a pointer, it is equally defined to accurately match. The equality of the structure refers to the accurate matching of bits (checks that include empty cavities due to alignment, usually they are set to zero during initialization). The equalization of floats is more complicated. -0 and 0 are equal. If the two operands are NAN, == and! = Operation will return false. In other cases, bit bit is more equal. For multiple plits, equal is defined as equivalent: x.re == y.re && x.im == y.im Not phase-defined as equivalent: X.re! = y.re || x.im! = y.im For class objects, equal is defined as the result of calling Object.eq (). If there is an object as NULL, it will throw an exception. As for static and dynamic arrays, equal is defined as equal to the length of the array, and the corresponding elements are equal. Same expression Equal expressions IS relationship expression Equalexpression is Relexpression IS is used to compare identity. If it is more unity, use ! (E1 IS E2). The type of result is a Boolean. Prior to comparison, the operands are transformed into one common type through common conversion transformation. If the operand is not a class object, a static or dynamic array, the identity is defined equivalent to equalization. For class objects, the identity is defined as reference to the same object. You can use the IS to compare null class objects. For static and dynamic arrays, identity is defined as pointing to the same array element. The same operator IS cannot be overloaded. Relational expression Relationship expression Relational expression <= shift expression Relationship expression> Displacement expression Relationship expression> = shift expression Relationship expression! <> = Shift expression Relationship expression! <> Shift expression Relationship expression <> shift expression Relational expression <> = shift expression Relationship expression!> Displacement expression Relationship expression!> = Shift expression Relationship expression! Relationship expression! <= Shift expression Relationship expression in shift expression Relevance Relevance <= shiftExpression Relevance> Shiftexpression Relevance> = shiftExpression Relevance! <> = Shiftexpression Relevance! <> Shiftexpression Relevance <> shiftExpression Relevance <> = shiftExpression Relevance!> Shiftexpression Relevance!> = ShiftExpression Relevance! Relevance! <= Shiftexpression Relevance in shiftexpression First, an integer is applied to an operand. The type of relationship expression returns the result is a Boolean. For class objects, the result of Object.cmp () constitutes the left operation, 0 constitutes the right operand. The result of the relationship expression (O1 OP O2) is: (O1.cmp (o2) op 0) If the object is NULL, it is an error. For static and dynamic arrays, the results of the relationship OP are the results of the operator to apply to the first unequal element in the array. If the two arrays are equal, but the length is different, the shorter array "less than" a longer array. Integer comparison If the two operands are integer types, they will perform an integer comparison. Integer comparison operator Operator relationship If <, <=,> or> = expression in the expression is a symbol number, the other operand is unsigned, and it is considered an error. You can use the type conversion to transform the two operands to the same number or no symbol number. Floating point comparison If the operand is the number of floats, the floating point is performed. Any floating point operation with practical value must support the NAN value. In particular, the relationship operator supports the NAN operand. The result of the relationship between floating point numbers can be less than, greater than, equal to or undefined (undefined means to have an operand NAN). This means there is 14 possible comparison conditions: Floating point comparison operator The operator is greater than it is less than or equal to the undefined anomalous relationship == FFTF NO is equal to! = TTFT NO Undefined, less than or greater than> TFFFFFFFFFFFFFFTF = fttf yes is less than or equal to or equal to or equal! <> = FFFT NO Undefined <> TTFF YES is less than or greater than <> = tttf yes is less than, equal to or greater than! <= TFFT NO Undefined or greater than! note: For floating point comparison operators, (a! Op b) is not equivalent to! (A OP B). The "undefined" means that there is an operand nan. "Abnormal" means that if the operand is NAN, INVALID exception is thrown.
