sample3.js

function myFunction() {
  
  var response = UrlFetchApp.fetch("https://so2-api.mutoys.com/json/sale/all.json");
  
  var json = JSON.parse(response.getContentText());
  
  var id = "sheetID";
  var spreadSheet = SpreadsheetApp.openById(id); 
  var sheet = spreadSheet.getSheetByName("シート1");
  
  var cellx = 2;
  var celly = 3;
  var pitems = sheet.getRange("A3").getValue();
  
  var price = [];
  var unit = [];
  var n = 0;
  
  while(1){
    try{
      var item = json[n]["item_id"];
      var area = json[n]["area_id"];
      
      if(item == 106){
        if(area == 2){
          var p = json[n]["price"];
          var u = json[n]["unit"];
          price.push(p);
          unit.push(u);
        }
      }
      n++;
    }
    catch(e){
      break;
    }
  }
  
  for(var n=0; n<price.length; n++){
    var value = sheet.getRange(celly + n , cellx);
    value.setValue(price[n]);
    value = sheet.getRange(celly + n, cellx + 1);
    value.setValue(unit[n]);
  }
  for(var n=0; n<pitems - price.length; n++){
    var values = sheet.getRange(celly + price.length + n , cellx);
    values.clear();
    values = sheet.getRange(celly + price.length + n , cellx + 1);
    values.clear(); 
  }
  
  sheet.getRange("A3").setValue(price.length);
}