javascript - Why isn't this recognized as a function? -

i have function in object:

var time = {      warps : 3,     warpcounter : 50,      warp : function(){         if (this.warps > 0){             this.warps--;             this.warploop = 50;             this.warploop();          }     },      warploop : function(){        settimeout(function () {           this.increment();                         if (warpcounter--){             this.warploop();           }else{             if(this.warps > 0){               htmlinteraction.enablebutton('warp-button');             }           }        }, 100);     },  }; 

when try , call method (using this.warploop()) get:

uncaught typeerror: property 'warploop' of object #<object> not function  

why this?

this context in settimeout changes, can use closures keep context.

var test={ warploop : function(){    var me=this;//set closure right context    settimeout(function () {      console.log("this is:",this); // window      console.log("me is:",me); // test      // can call me.warploop() not this.warploop()    }, 100); } } test.warploop(); 

your code can this:

var time = {      warps : 3,     warpcounter : 3,      warp : function(){         if (this.warps > 0){             this.warps--;             this.warploop = 50;             this.warploop();          }     },      warploop : function(){        //the settimeout calls me.warpcounter not this.warpcounter        // wich same window.warpcounter since next        // line not part of settimeout execution can        // use        console.log("warploop called,warpcounter is",this.warpcounter);        var me=this;        settimeout(function () {           //me.increment();                         if (me.warpcounter--){             me.warploop();           }else{             if(me.warps > 0){               //htmlinteraction.enablebutton('warp-button');             }           }        }, 100);     },  }; time.warploop();