javascript - for loop with functions -


this question has answer here:

i have (piece of) website, need grab data tvdb/the moviedb api. need screenshot of episode, use 

themoviedb.tvepisodes.getimages({ "id": showid, "season_number": season_number, "episode_number": episode_number }, function(data){}, function(error){})

i need execute 6 times, because need 6 images 6 different episodes. 

for(var = 0; < 7; i++){  }

but problem is, if ask console.log(i) inside function(data){} part, logs 6, 6 times...
what did wrong?

this full code, variables other functions etc...

      for(var = 0; < 6; i++) {     if = i;     u = + 1     eplen = data.episodes[data.episodes.length - 1 - i]   var thies = "<center><span style='font-family: arial'>" + eplen.season_number + 'x' + eplen.episode_number + ": <br>" + eplen.name + "<br>"+ eplen.air_date +"</span></center>";   var thisid = "recent" + u.tostring();   var text = thies;   document.getelementbyid(thisid).innerhtml = text;   themoviedb.tvepisodes.getimages({"id": showid, "season_number": eplen.season_number, "episode_number": eplen.episode_number},   function(data){     var data = json.parse(data);     window.still = data.stills[0].file_path;     console.log(window.still);     console.log(if); // logs 5     console.log(i); // logs 6 },   function(error){})   //alert(i)    //var still = window.still;   //console.log(still);   //var epstil = "https://image.tmdb.org/t/p/original" + still.stills[0].file_path;   //var epstill = "url(" + epstil + ")";   //document.getelementsbyclassname("recent")[i].style.backgroundimage = epstill;  }

edit
found solution, , since marked duplicate, can't answer anymore, i'll post here:

epstilarray = [];   for(var = 0; < 6; i++) {     if = i;     u = + 1     eplen = data.episodes[data.episodes.length - 1 - i]   var thies = "<center><span style='font-family: arial'>" + eplen.season_number + 'x' + eplen.episode_number + ": <br>" + eplen.name + "<br>"+ eplen.air_date +"</span></center>";   var thisid = "recent" + u.tostring();   var text = thies;   document.getelementbyid(thisid).innerhtml = text;   themoviedb.tvepisodes.getimages({"id": showid, "season_number": eplen.season_number, "episode_number": eplen.episode_number},   function(data){     var data = json.parse(data);     still = data.stills[0].file_path;     var epstil = "https://image.tmdb.org/t/p/original" + still;     var epstil = "url(" + epstil + ")";     epstilarray.push(epstil);     console.log(epstilarray);     document.getelementsbyclassname("recent")[epstilarray.length - 1].style.backgroundimage = epstil; },   function(error){}) }

this great example of spot can use javascript closure ensure each instance of inline function has access different value i.

one way wrap code in immediately-invoked function expression (iife), , capture copy of desired variable inside different variable tied scope of function expression. done in format of (function(){ var icopy = i; /*your code here*/})(); or (function(icopy){ /*your code here*/})(i);

setting copied variable in own line within iife:

for(var = 0; < 6; i++) {     ...     (function(){         var icopy = i; // copied icopy         themoviedb.tvepisodes.getimages({},             function(data){                 ...                 console.log(icopy);              }, function(error){});     })(); // iife has own scope capturing copy of variable  }

alternatively, passing variable parameter iife:

for(var = 0; < 6; i++) {     ...     (function(icopy){ // copied icopy         themoviedb.tvepisodes.getimages({},             function(data){                 ...                 console.log(icopy);              }, function(error){});     })(i); // iife has own scope capturing copy of variable parameter }

also note don't have change copied variable's name; did in above example sake of clarity. if 2 variables in different scopes share same name, code reference more immediate (innermost) scope. hence, following code work:

for(var = 0; < 6; i++) {     ...     (function(i){ // copied         themoviedb.tvepisodes.getimages({},             function(data){                 ...                 console.log(i);              }, function(error){});     })(i); // iife has own scope capturing copy of variable parameter }

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