Skills of the javascript delayed repeated execution function looprun. js_javascript

What is the repeated execution function of javascript latency? 1.1.23 function looprun (sFuncLoop, sFuncEnd, nDelay ){
// Writen by http://fengyan.iecn.cn

// SFuncLoop> string type, Javascript Functions or statements that need to be executed repeatedly (use; To separate multiple functions or statements)
// SFuncEnd> string type, used to stop Javascript Functions or statements that execute repeated actions (sFuncLoop)
// NDelay> Number type, recurrence interval (in milliseconds)
Var vintervalId = null;
Var runString = sFuncLoop;
Var stopString = sFuncEnd;
Var delayTime = nDelay;
// Var nCount = 0; // number of executions // to facilitate testing, comment out this line during the application
This. _ doLoop = function (){
If (vintervalId &&! Eval (stopString )){
Eval (runString );
// NCount ++; // record the execution times. // This line is commented out when the application is used for testing.
} Else {
Window. clearInterval (vintervalId );
VintervalId = null;
}
// Document. getElementById ("TestCount"). innerHTML = nCount; // number of output executions // comment out this line for ease of test
}
Window. clearInterval (vintervalId );
VintervalId = window. setInterval (this. _ doLoop, delayTime );
}

Several instance codes:
Horizontal Reciprocating Motion:



Looprun. js application example: Horizontal Reciprocating