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JavaScript Conditionals

Conditional Statements

Conditional Statements allow us to perform different actions for different conditions .

Conditional statements run different code depending on true or false conditions.

Conditional statements include

  • if
  • if...else
  • if...else if...else
  • switch
  • ternary (? :)

When to use Conditionals

  • Use if to specify a code block to be executed, if a specified condition is true
  • Use else to specify a code block to be executed, if the same condition is false
  • Use else if to specify a new condition to test, if the first condition is false
  • Use switch to specify many alternative code blocks to be executed
  • Use (? :) (ternary) as a shorthand for if...else

The if Statement

Use if to specify a code block to be executed, if a specified condition is true .

Syntax

if (
condition
) {
 //
 code to execute if the condition is true
}

The else Statement

Use else to specify a code block to be executed, if the same condition is false .

Syntax

if (
condition
) {
 //
 code to execute if the condition is true
}
else {
 //
 code to execute if the condition is false
}

The else if Statement

Use else if to specify a new condition to test, if the first condition is false .

Syntax

if (
condition1
) {
 //
 code to execute if condition1 is true
}
else if (
condition2
) {
 //
 code to execute if the condition1 is false and condition2 is true
} else {
 //
 code to execute if the condition1 is false and condition2 is false
}

The switch Statement

Use switch to specify many alternative code blocks to be executed.

Syntax

switch(
expression
) {
 case
x
 // code block
 break;
 case
y
 // code block
 break;
 default:
 //
code block
 }

Ternary Operator (? :)

Use (? :) (ternary) as a shorthand for if...else .

Example

condition
 ?
expression1
expression2

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This chapter

Overview
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Lessons

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Read time

1. JavaScript Tutorial2. JavaScript Syntax3. JavaScript Operators4. JavaScript if5. JavaScript Loops6. JavaScript Functions7. JavaScript Scope8. JavaScript Data Types9. JavaScript Style Guide10. JavaScript Introduction11. JavaScript Statements12. JavaScript Arithmetic13. JavaScript else14. JavaScript For Loop15. JavaScript Functions16. JavaScript Code Blocks17. JavaScript Primitives18. JavaScript Best Practices19. JavaScript Where To20. JavaScript Comments21. JavaScript Assignment22. The JavaScript Ternary Operator23. JavaScript While Loops24. Invoking JavaScript Functions25. JavaScript Hoisting26. JavaScript Built-In Objects27. JavaScript Common Mistakes28. JavaScript Output29. JavaScript Variables30. JavaScript Comparison31. JavaScript Switch Statement32. JavaScript Break33. JavaScript Function Parameters34. JavaScript Use Strict35. JavaScript typeof36. JavaScript Performance37. JavaScript Let38. JavaScript Conditionals39. JavaScript Booleans40. JavaScript Continue41. JavaScript Function Return42. JavaScript toString()43. JavaScript Const44. JavaScript Logical Operators45. JavaScript Control Flow46. JavaScript Function Arguments47. JavaScript Type Conversion48. JavaScript Datatypes49. JavaScript Function Expressions50. JavaScript Destructuring51. JavaScript Arrow Functions

On this page

Conditional StatementsWhen to use ConditionalsThe if StatementThe else StatementThe else if StatementThe switch StatementTernary Operator (? :)