Chapter 7: Arithmetic Expressions 7 Operand Evaluation Order Order of evaluation is crucial A = B + C Get value for B, get value for C, add the values Get value for C, Get value for B, add the values Function references is when order of evaluation is most crucial Functional side-effects Chapter 7: Arithmetic Expressions 8 Side Effects
before another. a - a it would be an expression evaluation, there's a sequence point at the end of every evaluation but not in between, therefore the increment of the first a++ is unexpected and the second it would only happen afterwards; moreover the order of precedence is nullified.
Expression evaluation in c
C Expressions. An expression is a formula in which operands are linked to each other by the use of operators to compute a value. An operand can be a function reference, a variable, an array element or a constant.
Lazy Evaluation. If expressions are only evaluated as-needed, or on demand, or only-if-needed, evaluation is said to be lazy. Otherwise it's eager. def first(x, y): return x first(f(), g()) Under eager evaluation, both f and g are called, and the results of each are passed to first. Under lazy evaluation, only f gets called.
Postfix Evaluation using stack is one such data structure that our compilers and interpreters use to evaluate any expression. They do not directly evaluate any infix expression using operator preference, instead of that they firstly convert any given infix expression into postfix expression and then evaluate it.