Booleans

Booleans are the "true" and "false" values

Booleans將通過比較產生

20 > 2; // true

    2 >= 2; // true

    5 < 5; // false

    5 <= 10; // true

    20 == 20; // true

    'john' == 'johnny' // false

    'a' == 'A' // false

    20 === "20"; // false - same value but different types

    20 != 10; // true

    10 != 10; // false

    "10" !== 10; // true - type is different

    /* 
    Be careful when using greater than and less than operators with different data types. 
    That can lead to unexpected results 
    */

Booleans可進行判斷式

var orderValue = 2800;

    if( orderValue >= 1000 ) {
        console.log("You are eligible to finance your order.");
    } else {
        console.log("Finance options are not available for orders below US$1000");
    }