Constrict a value to an interval. If the value exceeds one of the boundaries, the result will hold the exceeded boundary.

minmax.js

var value = -50;
var max = 0;
var min = -30;
var result = value;
if (result >= max) {
  result = max;
} else if (result < min) {
  result = min;
}
console.log('result with ifs: ' + result);

// A much more elegant solution using Math.min and Math.max
result = value;
result = Math.min(max,Math.max(result,min));
console.log('result with Math.max and Math.min: ' + result);