Count values of the inner two-dimensional array - javascript -

i have two-dimensional array. i'm trying count values within inner array. i'm aware of js array.length. doing testdata.length yields 5. accurate. however, want count number of items within each sub array.

testdata[0].length yield 6. how dynamically count through each sub array? (as change).

var testdata = [["column1","test1","test1","tea","party", "water bottle"],                 ["column2","test2","test2","test2 test2"],                 ["column3","test2","test2","test2 test2 "],                 ["column4","test2","test2 test2f asdfsdf"],                 ["column5","test2","test2 test2f asdfsdfasdfasdfasa asda asdfsas"] ] 

var testdata = [["column1","test1","test1","tea","party", "water bottle"],                 ["column2","test2","test2","test2 test2"],                 ["column3","test2","test2","test2 test2 "],                 ["column4","test2","test2 test2f asdfsdf"],                 ["column5","test2","test2 test2f asdfsdfasdfasdfasa asda asdfsas"] ]; for(var i=0;i < testdata.length;i++){   for(var j=0;j<testdata[i].length;j++){     alert(testdata[i][j]);   } }