js--复选框--全选、反选、取消

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//第一种方法：存在不足之处

//全选、反选、取消

//全选

function selectAll() {

for (i = 0; i < document.form.missiveType.length; i++) {

if (!document.form.missiveType[i].checked) {

document.form.missiveType[i].checked = true;

}

}

}

//反选

function selectRerverse() {

for (i = 0; i < document.form.missiveType.length; i++) {

if (document.form.missiveType[i].checked) {

document.form.missiveType[i].checked = false;

} else {

document.form.missiveType[i].checked = true;

}

}

}

//取消

function cancelAll() {

for (i = 0; i < document.form.missiveType.length; i++) {

if (document.form.missiveType[i].checked) {

document.form.missiveType[i].checked = false;

}

}

}

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第二种方法：较好

//全选、反选、取消

//全选

function selectAll() {

var es=document.getElementsByName("missiveType");

for (i = 0; i < es.length; i++) {

if (!es[i].checked) {

es[i].checked = true;

}

}

}

//反选

function selectRerverse() {

var es=document.getElementsByName("missiveType");

for (i = 0; i < es.length; i++) {

if (es[i].checked) {

es[i].checked = false;

} else {

es[i].checked = true;

}

}

}

//取消

function cancelAll() {

var es=document.getElementsByName("missiveType");

for (i = 0; i < es.length; i++) {

if (es[i].checked) {

es[i].checked = false;

}

}

}