If...else Statement

Use the if....else statement to execute some code if a condition is true and another code if the condition is not true.

Syntax

if (condition)   {   code to be executed if condition is true   } else   {   code to be executed if condition is not true   }

Example <script type="text/javascript"> //If the time is less than 10, you will get a "Good morning" greeting. //Otherwise you will get a "Good day" greeting. var d = new Date(); var time = d.getHours(); if (time < 10)   {   document.write("Good morning!");   } else   {   document.write("Good day!");   } </script>

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If...else if...else Statement

Use the if....else if...else statement to select one of several blocks of code to be executed.

Syntax

if (condition1)   {   code to be executed if condition1 is true   } else if (condition2)   {   code to be executed if condition2 is true   } else   {   code to be executed if condition1 and condition2 are not true   }

Example <script type="text/javascript"> var d = new Date() var time = d.getHours() if (time<10)   {   document.write("<b>Good morning</b>");   } else if (time>10 && time<16)   {   document.write("<b>Good day</b>");   } else   {   document.write("<b>Hello World!</b>");   } </script>