How to declare variables in different ways in JavaScript?

In JavaScript, we can declare a variable in different ways by using different keywords. Each keyword holds some specific reason or feature in JavaScript. Basically we can declare variables in three different ways by using var, let and const keyword. Each keyword is used in some specific conditions.

var: This keyword is used to declare variable globally. If you used this keyword to declare variable then the variable can accessible globally and changeable also. It is good for a short length of codes, if the codes get huge then you will get confused.

  • Syntax:
    var variableName = "Varable-Value;"
  • Code:
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    <script>
        var geeks = "GeeksforGeeks";
        console.log(geeks);
    </script>

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  • Output:
    GeeksforGeeks

let: This keyword is used to declare variable locally. If you used this keyword to declare variable then the variable can accessible locally and it is changeable as well. It is good if the code gets huge.



  • Syntax:
    let variableName = "Varable-Value;"
  • Code:
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    <script>
    if (true) {
        let geeks = "GeeksforGeeks";
        console.log(geeks);
        }
          
        /* This will be error and 
           show geeks is not defined */
        console.log(geeks);
    </script>

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  • Output:
    GeeksforGeeks

const: This keyword is used to declare variable globally. If you used this keyword to declare variable then the variable can accessible globally and it is not changeable.

  • Syntax:
    var variableName = "Varable-Value;"
  • Code:
    filter_none

    edit
    close

    play_arrow

    link
    brightness_4
    code

    <script>
        const geeks = "GeeksforGeeks";
        console.log(geeks);
    </script>

    chevron_right

    
    

  • Output:
    GeeksforGeeks



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