JAVASCRIPT SWITCH STATEMENT
In the previous chapter we have learned that if else statement is used for
decision making. We can execute a block of code when a certain condition is satisfied.
switch statement
is also used for the same purposes to make decisions on some conditions.
switch statement
switch statement
is a conditional statement same as 'if else' statement. switch
statement is a flow-control statement. It is used to control complex conditional operations.
switch statement is more convenient to use in some cases, like when we have to check for a variable
with hundreds of conditions.
Syntax :
switch (expression) { case condition_1: // execute this block if the condition is true... break; case condition_2: // execute this block if the condition is true... break; case condition_3: // execute this block if the condition is true... break; . . . default: // execute this block if no condition is true... }
Example
Lets see how this work:
- First expression in switch statement is evaluated
- Then the value found by evaluating expression is matched with condition of each case (condition can be number, string, expression, boolean)
- if value matched then block of code for that case is executed
- then
break
command breaks through the switch statement. - In case no condition matched then code block of default section is executed
Matching switch expression with multiple cases
In case you want to match switch expression with multiple cases to execute the same code block, for this just
write all cases that you want to match without break
command or expression and at the last case
write your code block with break command.
Example
Expression as condition in switch statement
In all above examples we have used numerical value as a condition but we can put anything as condition like number, string, boolean, expression etc.
Lets see an example:
Example