Js timer setTimeout cannot call local variables solution

The usage of timer setTimeout in javascript is generally as follows. After calling beginrotate, it enters a process of timing execution of rotateloop, as follows:

 
var angle = 0; 

function rotateloop() { 
if (angle < 360) { 
angle++; 
//use angle 
//...... 
setTimeout("rotateloop()", 100); 
} 
} 

function beginrotate() { 
//do something 
//...... 
setTimeout("rotateloop()", 100); 
} 

This code has a problem, is produced a global variable Angle, which is obviously not a good programming habit, so we thought of using the way of embedded function, the code as follows:

 
function beginrotate() { 

var angle = 0; 

function rotateloop() { 
if (angle < 360) { 
angle++; 
//use angle 
//...... 
setTimeout("rotateloop()", 100); 
} 
} 
//do something 
//...... 
setTimeout("rotateloop()", 100); 
} 

After this is changed, found javascript error, rotateloop can not find, obviously setTimeout did not find the rotateloop this local nested function, here as long as a little change can solve the problem, the code is as follows:

 
function beginrotate() { 

var angle = 0; 

function rotateloop() { 
if (angle < 360) { 
angle++; 
//use angle 
//...... 
setTimeout(rotateloop, 100); 
} 
} 
//do something 
//...... 
setTimeout(rotateloop, 100); 
} 

All you need to do is change the first argument of setTimeout to a function object, not a string.