JavaScript数组基础操作详解：定义、排序、连接与增删改

vara=[1,2,3]
vara=newArray(1,2,3);

<script>
 vara=[1,2,3,4,5,6];
 alert(a.length);
</script>

<script>
 vara=[1,2,3,4,5,6];
 a.length=2;
 alert(a);
</script>

<script>
 vara=[1,2,3];
 varb=[4,5,6];
 alert(a.concat(b));
 alert(b.concat(a));
</script>

<script>
 vararr=['float','width','alpha','zoom','left'];
 arr.sort();
 alert(arr);
</script>

vararr=[12,8,99,19,112];
arr.sort();
alert(arr);

vararr=[12,8,99,19,112];
arr.sort(function(n1,n2){
 returnn1-n2;
});
alert(arr);

<script>
 vara=[1,2,3];
 varb=[4,5,6];
 alert(a.concat(b));
 alert(b.concat(a));
</script>

<script>
 vararr=[1,2,3,4];
 alert(arr.join('--p'));
</script>

<script>
 vara=[1,2,3];
 a.push(4);
 alert(a);
</script>

<script>
 vara=[1,2,3];
 a.pop();
 alert(a);
</script>

<script>
 vararr=[1,2,3];
 arr.unshift(0)
 alert(arr);
</script>

<script>
 vararr=[1,2,3];
 arr.shift();
 alert(arr);
</script>

<script>
 vararr=[1,2,3,4,5,6];
 //splice(起点，长度)
 arr.splice(2,3);
 alert(arr);
</script>

<script>
 vararr=[1,2,3,4,5,6];
 //插入数据splice（起点，长度，元素）
 arr.splice(2,0,'a','b','c');
 alert(arr);
</script>

<script>
 vararr=[1,2,3,4,5,6];
 //替换数据
 arr.splice(2,2,'a','b');
 alert(arr);
</script>