<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">
<title>live_exam</title>
</head>
<body>
<!-- <div>
<div style="float: left; 200px;margin-top: 20px; height: 100px; background: red"></div>
<div style="display: block;overflow: hidden; height: 400px; background: blue; margin-top: 50px"></div>
</div> -->
<div id="testId"></div>
</body>
<!-- <script src="./css/channel.js"></script> -->
</html>
<script type="text/javascript">
window.onload = function(){
var str = 'abcdefghijklmnhjkobnvcxz'
var arr = [[2,4],[6,8],[9,11],[20,21]]
var result = '';
for (var i=0; i <= arr.length-1; i++) {
console.log(arr.length-1,i)
if (arr.length > 1) {
if (i == 0) {
// console.log(1)
result += str.substring(0,arr[i][0]) + '<span style="color:red">' + str.substring(arr[i][0],arr[i][1] + 1) + '</span>'
//console.log(result)
} else if (i >0 && i< arr.length-1) {
//console.log(2)
result += str.substring(arr[i-1][1] + 1,arr[i][0]) + '<span style="color:red">' + str.substring(arr[i][0],arr[i][1] +1) + '</span>'
//console.log(result)
} else if (i == arr.length-1) {
//console.log(result)
//console.log(4)
result += str.substring(arr[i-1][1] + 1,arr[i][0]) + '<span style="color:red">' +str.substring(arr[i][0],arr[i][1] + 1) + '</span>' + str.substring(arr[i][1]+ 1)
}
} else {
result += str.substring(0,arr[i][0]) + '<span style="color:red">' + str.substring(arr[i][0],arr[i][1] + 1) + '</span>' + str.substring(arr[i][1]+ 1)
}
}
document.getElementById('testId').innerHTML = result
//console.log(result)
}
var text = 'ad$$1a$$nihao$$67$$nihao$$'
var reg = /$$.*?$$/ig;
var arr = []
//var reg10 = /http(s)?:/ig;
//var str2 = text.replace(reg,'')
var str2 = text.replace(reg,function(exp){
console.log('-----------')
console.log(exp)
arr.push(exp)
//console.log(exp.replace(reg10,''))
//return exp.replace(reg10,'');
})
console.log(arr)
</script>