javascript权威指南-数据类型笔记
原始值与应用值1.原始值类型数据室不可变的 (改变原始值类型数据, 返回的是一个新的对象)
var str0 = 'test';var str1 = str.replace('t', 'a');alert(str1); // 输出 'aest'alert(str0); // 输出 'test'
2.应用值类型是可变的(他的值是可以修改的)
// 对象直接量var o = {x:1, y:2, z:3};console.log(o); // 输出 Object { x=1, y=2, z=3}o.z = 4;console.log(o); // 输出 Object { x=1, y=2, z=4}// 数组直接量var arr = [1, 2, 3];console.log(arr) // 输出 [1,2,3]arr[2] = 4;console.log(arr) // 输出[1, 2,4]
几个知识点1.Javascript是ECMAscript的实现,其组成部分有:
2. 原始类型与引用类型(以下是w3school的解释很清晰)原始值: 存储在栈(stack)中的简单数据段，也就是说，它们的值直接存储在变量访问的位置。
引用值: 存储在堆（heap）中的对象，也就是说，存储在变量处的值是一个指针（point），指向存储对象的内存处。
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