Types of Logical Operators in Java
In Java, logical operators are used to manipulate boolean values. There are three types of logical operators in Java:
In the example above, the AND operator returns true because both x is greater than 3 and y is less than 10.
In the example above, the OR operator returns true because y is less than 10, even though x is not greater than 10.
In the example above, the NOT operator reverses the value of x from true to false, so the else block is executed. First, it is important to note that logical operators evaluate their operands from left to right, and stop as soon as the result of the expression can be determined. This means that in an expression such as A && B, if A is false, B will not be evaluated, because the whole expression will already be false.Second, logical operators can also be used with non-boolean expressions, but they will first be converted to boolean values using the following rules:
For example, the following code will print "At least one value is non-zero":
In this case, x is 0, which is considered false, but y is 7, which is considered true, so the OR operator returns true. Third, logical operators can be combined in more complex expressions, using parentheses to control the order of evaluation. For example, the following code will print "Both conditions are true":
In this case, the expression (x > 3 && y < 10) is evaluated first, and returns true, because both conditions are true. Then, the expression (z == 3 && x <= 5) is evaluated, and returns false, because x is greater than 5. Finally, the OR operator combines the two results, and returns true, because at least one of the expressions is true. Overall, logical operators are a powerful tool for manipulating boolean values and making decisions in Java programs. It is important to understand their behavior and how to use them effectively in complex expressions.
In this case, if str is null, the first condition str != null will be false, and the second condition str.length() > 0 will not be evaluated, because the whole expression will already be false. This prevents a NullPointerException from being thrown when trying to access the length of a null string.
In this case, x and y are represented in binary as 101 and 110, respectively. The bitwise AND operator compares the corresponding bits of x and y, and sets each bit of the result to 1 if both bits are 1. The result is 100, which represents the decimal value 4.
In this case, the expression inside the parentheses is evaluated first, which returns false, because x is not equal to 6. Then, the NOT operator is applied to the result, which reverses it to true.
In this case, the boolean expression x > y is true, so the first operand of the ternary operator is returned, which is the string "x is greater than y".
In this case, the expression x == 3 || y == 4 evaluates to false, because neither condition is true. Then, the NOT operator is applied to the result, which makes the whole expression true, according to De Morgan's laws.
In this case, the OR operator is applied to x and the value 2, which sets the second bit of x to 1. The result is 7, which is assigned back to x.
In this case, the relational operator > is used to compare x and y, and the expression evaluates to true, because x is greater than y.