Types of expressions in C++.

Q2. What types of expressions can be formed in C++? Discuss each one of them with examples.

Ans. The expressions in C++ can be any type: arithmetic expression, relational (or logical) expression, compound expression etc.

1. Arithmetic Expressions

Arithmetic expressions can either be integer expressions or real expressions. Sometimes a mixed expression can also be formed which is a mixture of real and integer expressions.

Integer expressions are formed by connecting integer constants and/or integer variables using integer arithmetic operators.

The following are valid integer expressions:

const count = 30;

int I, J, K, Y, Z;

• I
• –J
• K –X
• K+X – Y + count
• –J +K *Y
• J/Z
• Z % X

Real expressions are formed by connecting real constants and/or real variables using real arithmetic operators (for example, % is not a real arithmetic operator).

The following are valid real expressions:

const bal = 250.53;

float qty, amount, value;

double fin, inter;

• qty/amount
• qty * value
• (amount + qty * value) – bal
• fin + qty * inter
• inter – (qty * value) + fin

2. Logical Expressions

The expressions that results into 0 (false) or 1 (true) are called logical expressions. The logical expressions are combination of constants, variables and logical and relational operators.

The rule for writing logical expressions states:

A logical expression may contain just one signed or unsigned variable or a constant, or it may have two or more variables or/and constants, or two or more expressions joined by valid relational and/or logical operators. Two or more variables or operators should not occur in continuation.

The following are examples of some valid logical expressions:

• x>y
• (y+z)>=(x/z)
• (a+b)>c&&(c+d)>a
• (y>x)||(z<y)
• x||y&&z
• (x)
• (-y)
• (x-y)
• (x>y)&&(!y<z)
• x<=!y&&z