autojs[javascript]截取两个字符串中间的值

例如
var str = ‘高中10人;专科20人;本科30人;’;//取10或20或30
var firstStr=’高中’;
var secondStr=’人’;

走下面的js方法取到10

function getNum(str,firstStr,secondStr){
if(str == "" || str == null || str == undefined){ // "",null,undefined
return "";
}
if(str.indexOf(firstStr)<0){
return "";
}
var subFirstStr=str.substring(str.indexOf(firstStr)+firstStr.length,str.length);
var subSecondStr=subFirstStr.substring(0,subFirstStr.indexOf(secondStr));
return subSecondStr;
}

function getValue( key1,key2, str ) { 
    
    var m = str.match( new RegExp(key1+'(.*?)'+key2) );
    
    return m ? m[ 1 ] : false;
}

var str = '{"success":true,"message":"修改成功"}';
 
res=getValue( 'success":',',"', str ); // return true
console.log(res)
 
res=getValue( 'message":"','"}', str ); // return 修改成功
 console.log(res)