JavaScript基础知识(五)

时间 2019-11-24

原文原文链接

41 建立幻灯片

1: <script language=”JavaScript”>
2: var p_w_picpathList = new Array;
3: p_w_picpathList[0] = new Image;
4: p_w_picpathList[0].src = “p_w_picpath1.jpg”;
5: p_w_picpathList[1] = new Image;
6: p_w_picpathList[1].src = “p_w_picpath2.jpg”;
7: p_w_picpathList[2] = new Image;
8: p_w_picpathList[2].src = “p_w_picpath3.jpg”;
9: p_w_picpathList[3] = new Image;
10: p_w_picpathList[3].src = “p_w_picpath4.jpg”;
11: function slideShow(p_w_picpathNumber) {
12: document.slideShow.src = p_w_picpathList[p_w_picpathNumber].src;
13: p_w_picpathNumber += 1;
14: if (p_w_picpathNumber < p_w_picpathList.length) {
15: window.setTimeout(“slideShow(“ + p_w_picpathNumber + “)”,3000);
16: }
17: }
18: </script>
19: </head>
20: <body onLoad=”slideShow(0)”>
21: <img src="/”p_w_picpath1.jpg"” width=100 name=”slideShow”>

42 随机广告图片

1: <script language=”JavaScript”>
2: var p_w_picpathList = new Array;
3: p_w_picpathList[0] = “p_w_picpath1.jpg”;
4: p_w_picpathList[1] = “p_w_picpath2.jpg”;
5: p_w_picpathList[2] = “p_w_picpath3.jpg”;
6: p_w_picpathList[3] = “p_w_picpath4.jpg”;
7: var urlList = new Array;
8: urlList[0] = “ [url]http://some.host/[/url] ”;
9: urlList[1] = “ [url]http://another.host/[/url] ”;
10: urlList[2] = “ [url]http://somewhere.else/[/url] ”;
11: urlList[3] = “ [url]http://right.here/[/url] ”; 12: var p_w_picpathChoice = Math.floor(Math.random() * p_w_picpathList.length); 13: document.write(‘<a href=”’ + urlList[p_w_picpathChoice] + ‘“><img src=”’ + p_w_picpathList[p_w_picpathChoice] + ‘“></a>’); 14: </script> JavaScript就这么回事4：表单仍是先继续写完JS就这么回事系列吧～ 43 表单构成 1: <form method=”post” action=”target.html” name=”thisForm”> 2: <input type=”text” name=”myText”> 3: <select name=”mySelect”> 4: <option value=”1”>First Choice</option> 5: <option value=”2”>Second Choice</option> 6: </select> 7: <br> 8: <input type=”submit” value=”Submit Me”> 9: </form> 44 访问表单中的文本框内容 1: <form name=”myForm”> 2: <input type=”text” name=”myText”> 3: </form> 4: <a href='#'>Check Text Field</a> 45 动态复制文本框内容 1: <form name=”myForm”> 2: Enter some Text: <input type=”text” name=”myText”><br> 3: Copy Text: <input type=”text” name=”copyText”> 4: </form> 5: <a href=”#” onClick=”document.myForm.copyText.value = 6: document.myForm.myText.value;”>Copy Text Field</a> 46 侦测文本框的变化 1: <form name=”myForm”> 2: Enter some Text: <input type=”text” name=”myText” onChange=”alert(this.value);”> 3: </form> 47 访问选中的Select 1: <form name=”myForm”> 2: <select name=”mySelect”> 3: <option value=”First Choice”>1</option> 4: <option value=”Second Choice”>2</option> 5: <option value=”Third Choice”>3</option> 6: </select> 7: </form> 8: <a href='#'>Check Selection List</a> 48 动态增长Select项 1: <form name=”myForm”> 2: <select name=”mySelect”> 3: <option value=”First Choice”>1</option> 4: <option value=”Second Choice”>2</option> 5: </select> 6: </form> 7: <script language=”JavaScript”> 8: document.myForm.mySelect.length++; 9: document.myForm.mySelect.options[document.myForm.mySelect.length - 1].text = “3”; 10: document.myForm.mySelect.options[document.myForm.mySelect.length - 1].value = “Third Choice”; 11: </script> 49 验证表单字段 1: <script language=”JavaScript”> 2: function checkField(field) { 3: if (field.value == “”) { 4: window.alert(“You must enter a value in the field”); 5: field.focus(); 6: } 7: } 8: </script> 9: <form name=”myForm” action=”target.html”> 10: Text Field: <input type=”text” name=”myField”onBlur=”checkField(this)”> 11: <br><input type=”submit”> 12: </form> 50 验证Select项 1: function checkList(selection) { 2: if (selection.length == 0) { 3: window.alert(“You must make a selection from the list.”); 4: return false; 5: } 6: return true; 7: }