js数组追加数组

JavaScript013

js数组追加数组,第1张

你这个数据写的太乱了 我就说个思路吧

比如 2个数组合成第三个数组

var arr1=['a','b']

var arr2=[1,2]

var arr3=[]

for(i=0i<arr1.lengthi++){

    var j=[]

    j.push(arr1[i])

    j.push(arr2[i])

    arr3.push(j)

}

利用堆栈的压栈成立新的数组

js动态添加数组可以按下面的步骤:

1、在数组的开头添加新元素 - unshift()

源代码:

<!DOCTYPE html>

<html>

<body>

<p id="demo">Click the button to add elements to the array.</p>

<button onclick="myFunction()">Try it</button>

<script>

function myFunction()

{

var fruits = ["Banana", "Orange", "Apple", "Mango"]

fruits.unshift("Lemon","Pineapple")

var x=document.getElementById("demo")

x.innerHTML=fruits

}

</script>

<p><b>Note:</b>The unshift() method does not work properly in Internet Explorer 8 and earlier, the values will be inserted, but the return value will be <em>undefined</em>.</p>

</body>

</html>

测试结果:

Lemon,Pineapple,Banana,Orange,Apple,Mango

2、在数组的第2位置添加一个元素 - splice()

源代码:

<!DOCTYPE html>

<html>

<body>

<p id="demo">Click the button to add elements to the array.</p>

<button onclick="myFunction()">Try it</button>

<script>

function myFunction()

{

var fruits = ["Banana", "Orange", "Apple", "Mango"]

fruits.splice(2,0,"Lemon","Kiwi")

var x=document.getElementById("demo")

x.innerHTML=fruits

}

</script>

</body>

</html> 

测试结果:

Banana,Orange,Lemon,Kiwi,Apple,Mango

3、数组的末尾添加新的元素 - push()

源代码:

<!DOCTYPE html>

<html>

<body>

<p id="demo">Click the button to add a new element to the array.</p>

<button onclick="myFunction()">Try it</button>

<script>

var fruits = ["Banana", "Orange", "Apple", "Mango"]

function myFunction()

{

fruits.push("Kiwi")

var x=document.getElementById("demo")

x.innerHTML=fruits

}

</script>

</body>

</html>

测试结果:

Banana,Orange,Apple,Mango,Kiwi

需要准备的材料分别是:电脑、html编辑器、浏览器。

1、首先,打开html编辑器,新建html文件,例如:index.html。

2、以追加name元素为例,在index.html的<script>标签中,输入js代码:

var names = ['Alice', 'Bob']

var json = []

for (var i = 0i <names.lengthi++) {

json[i] = {'name' : names[i]}

}

document.body.innerText = JSON.stringify(json)

3、浏览器运行index.html页面,此时会打印出追加name元素后的json数组。