如何将元素ID传递给函数的参数？ HTML / JS

Question

function ValueLimit(min, max, mode){

        var v;
        if(mode === "h"){
            v = document.getElementById("weight_imp").value;

            if(v < min){document.getElementById("weight_imp").value = min;}
            if(v > max){document.getElementById("weight_imp").value = max;}
        }

        if(mode === "w"){
            v = document.getElementById("weight_imp").value;

            if(v < min){document.getElementById("weight_imp").value = min;}
            if(v > max){document.getElementById("weight_imp").value = max;}
        }
    }

I need to replace mode with an ID of an input element This should in turn make the code significantly smaller I cannot seem to find a way to pass it through It should be able to target any element on the page

Answer 1

I would suggest that you pass your function an actual element instead of a selector (which has the added benefit of not requiring every input to have an id ). You can also make the implementation much shorter using Math.min and Math.max .

 function clampValue (e, min, max){ e.value = Math.min(max, Math.max(min, +e.value)) } var input = document.getElementById('weight_imp') function exampleUsage () { clampValue(input, 0, 100) } 

 <input type="number" id="weight_imp"> <button onclick="exampleUsage()">Clamp [0, 100]</button>