js 学习笔记

// firebug 查看 打印console.log()用法

<script type="text/javascript">
//变量
var i = 'I am a string';
console.log('变量：',i);
//数组
var arr = [1,2,3,4,5];
console.log('数组：',arr);
//对象
var obj1 = {
    key1 : 'value1',
    key2 : 'value2',
    key3 : 'value3'
};
var obj2 = {
    key6 : 'value4',
    key5 : 'value5',
    key4 : 'value6'
};
var obj3 = {
    key9 : 'value7',
    key8 : 'value8',
    key7 : 'value9'
};
console.log('对象：',obj1);
//对象数组
var objArr1 = [obj1,obj2,obj3];
var objArr2 = [[obj1],[obj2],[obj3]];

console.log('对象数组1：',objArr1);
console.log('对象数组1：',objArr2);
</script>

输出：

变量：I am a string

数组：[1, 2, 3, 4, 5]

对象：Object { key1="value1", key2="value2", key3="value3"}

对象数组1：[Object { key1="value1", key2="value2", key3="value3"}, Object { key6="value4", key5="value5", key4="value6"}, Object { key9="value7", key8="value8", key7="value9"}]

对象数组1：[[Object { key1="value1", key2="value2", key3="value3"}], [Object { key6="value4", key5="value5", key4="value6"}], [Object { key9="value7", key8="value8", key7="value9"}]]



//js验证输入中文
姓：<input type="txt" name="xing" size="4" value="" on

Keypress="if ((event.keyCode != 13 && event.keyCode < 160)) event.returnValue = false;">
   名：<input type="txt" name="ming" size="4" value="" onKeypress="if ((event.keyCode != 13 && event.keyCode < 160)) event.returnValue = false;">

//ie 下 js textarea 统计字数 onpropertychange事件 

<textarea id="textcont" name="textcont" cols="100" rows="24" onpropertychange="textCounter(this)"></textarea>

function textCounter(field) {
if (field.value.length > 5000)
   document.getElementById('zi1').innerText = '(5000)';
else
   document.getElementById('zi1').innerText = '';
   document.getElementById('zi0').innerText =  field.value.length;
}