JavaScript language includes operators that compare two operands and return Boolean value true or false.
== Compares the equality of two operands without considering type. === Compares equality of two operands with type. != Compares inequality of two operands. **> ** Checks whether left side value is greater than right side value. If yes then returns true otherwise false. < Checks whether left operand is less than right operand. If yes then returns true otherwise false. >= Checks whether left operand is greater than or equal to right operand. If yes then returns true otherwise false. <= Checks whether left operand is less than or equal to right operand. If yes then returns true otherwise false.
Example about it: var a = 5, b = 10, c = "5"; var x = a;
a == c; // returns true### this operators compare a value.
a === c; // returns false this operators compare a value and data type.
a == x; // returns true
a != b; // returns true
a > b; // returns false
a < b; // returns true
a >= b; // returns false
a <= b; // returns true
a >= c; // returns true
a <= c; // returns true
Logical operators are used to combine two or more conditions. JavaScript includes following logical operators.
&& && is known as AND operator. It checks whether two operands are non-zero (0, false, undefined, null or "" are considered as zero), if yes then returns 1 otherwise 0.
|| || is known as OR operator. It checks whether any one of the two operands is non-zero (0, false, undefined, null or "" is considered as zero).
! ! is known as NOT operator. It reverses the boolean result of the operand (or condition)
Looping in programming languages is a feature which facilitates the execution of a set of instructions/functions repeatedly while some condition evaluates to true.
Java provides three ways for executing the loops. While all the ways provide similar basic functionality, they differ in their syntax and condition checking time.
while loop: A while loop is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. The while loop can be thought of as a repeating if statement.
Syntax :
while (boolean condition)
{
loop statements...
}
for loop: for loop provides a concise way of writing the loop structure. Unlike a while loop, a for statement consumes the initialization, condition and increment/decrement in one line thereby providing a shorter, easy to debug structure of looping.
Syntax :
for (initialization condition; testing condition;
increment/decrement)
{
statement(s)
}
