js select常用操作控制代碼
2024-05-06 14:11:06
供稿：網(wǎng)友
// 1.判斷select選項(xiàng)中 是否存在Value="paraValue"的Item
function jsSelectIsExitItem(objSelect, objItemValue) {
var isExit = false;
for (var i = 0; i < objSelect.options.length; i++) {
if (objSelect.options[i].value == objItemValue) {
isExit = true;
break;
}
}
return isExit;
}
// 2.向select選項(xiàng)中 加入一個Item
function jsAddItemToSelect(objSelect, objItemText, objItemValue) {
//判斷是否存在
if (jsSelectIsExitItem(objSelect, objItemValue)) {
alert("該Item的Value值已經(jīng)存在");
} else {
var varItem = new Option(objItemText, objItemValue);
objSelect.options.add(varItem);
alert("成功加入");
}
}
// 3.從select選項(xiàng)中 刪除一個Item
function jsRemoveItemFromSelect(objSelect, objItemValue) {
//判斷是否存在
if (jsSelectIsExitItem(objSelect, objItemValue)) {
for (var i = 0; i < objSelect.options.length; i++) {
if (objSelect.options[i].value == objItemValue) {
objSelect.options.remove(i);
break;
}
}
alert("成功刪除");
} else {
alert("該select中 不存在該項(xiàng)");
}
}
// 4.刪除select中選中的項(xiàng)
function jsRemoveSelectedItemFromSelect(objSelect) {
var length = objSelect.options.length - 1;
for(var i = length; i >= 0; i--){
if(objSelect[i].selected == true){
objSelect.options[i] = null;
}
}
}
// 5.修改select選項(xiàng)中 value="paraValue"的text為"paraText"
function jsUpdateItemToSelect(objSelect, objItemText, objItemValue) {
//判斷是否存在
if (jsSelectIsExitItem(objSelect, objItemValue)) {
for (var i = 0; i < objSelect.options.length; i++) {
if (objSelect.options[i].value == objItemValue) {
objSelect.options[i].text = objItemText;
break;
}
}
alert("成功修改");
} else {
alert("該select中 不存在該項(xiàng)");
}
}
// 6.設(shè)置select中text="paraText"的第一個Item為選中
function jsSelectItemByValue(objSelect, objItemText) {
//判斷是否存在
var isExit = false;
for (var i = 0; i < objSelect.options.length; i++) {
if (objSelect.options[i].text == objItemText) {
objSelect.options[i].selected = true;
isExit = true;
break;
}
}
//Show出結(jié)果
if (isExit) {
alert("成功選中");
} else {
alert("該select中 不存在該項(xiàng)");
}
}
// 7.設(shè)置select中value="paraValue"的Item為選中
document.all.objSelect.value = objItemValue;
// 8.得到select的當(dāng)前選中項(xiàng)的value
var currSelectValue = document.all.objSelect.value;
// 9.得到select的當(dāng)前選中項(xiàng)的text
var currSelectText = document.all.objSelect.options[document.all.objSelect.selectedIndex].text;
// 10.得到select的當(dāng)前選中項(xiàng)的Index
var currSelectIndex = document.all.objSelect.selectedIndex;
// 11.清空select的項(xiàng)
document.all.objSelect.options.length = 0;
