javascript - i can't check whether an evaluated variable in undefined -

javascript - i can't check whether an evaluated variable in undefined -

i have next code in want eval concatenation , check whether it's defined or not,

var image1="images/pic1.png"; var image2="images/pic2.png"; var image3="images/pic3.png"; var image4="images/pic4.png"; /* var image5=""; var image6=""; var image7=""; var image8=""; var image9=""; var image10=""; var image11=""; var image12=""; */ var imagelink; var count=12; (i=0;i<count;i++){ var imagelink=eval("image"+(i+1)); if (typeof imagelink === "undefined"){ alert("imagelink undefined"); imagelink=""; }

so lastly piece doesn't work.

var images = []; images.push( 'images/pic1.png' ); images.push( 'images/pic2.png' ); images.push( 'images/pic3.png' ); images.push( 'images/pic4.png' ); var imagelink = ''; ( i=0; i<images.length; i++ ){ imagelink = images[ ]; if ( !imagelink ){ alert( 'imagelink undefined' ); imagelink = ''; } }

as recommended in comment, set info on array, , cycle through each element on for, way code gets cleaner , don't have eval.

javascript eval