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Boolean类型

可以先输出Boolean来观察下

        console.dir(new Boolean())

这个类型只有2个方法,并且都是重写Object的方法;

  • toString()
  • valueOf()

Boolean对象在实际使用中,用处并不大,

因为boolean数据就是用来判断真假的,而Boolean对象是做为对象来用的,任何非空对象转换的时候,都是true、;

new Boolean(false) //这种创建的Boolean是true的;

例子如下:

var falseObject = new Boolean(false);
var result = falseObject && true;
console.log(falseObject,result); //true,因为falseObject会被转为true;因为是当作对象来解析的;
var falseValue = false;
result = falseValue && true;
console.log(falseValue,result); //false

console.log(typeof falseObject); //object
console.log(typeof falseValue); //boolean
console.log(falseObject instanceof Boolean); //true
console.log(falseValue instanceof Boolean); //false

理解基本类型的布尔值与 Boolean 对象之间的区别非常重要——当然,我们的建议是永远不要使用 Boolean 对象。

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