Now, you'll see how to use Ext JS in order to guarantee that a number falls within a certain range.
The following steps illustrate how to perform range checking on numeric values:
1. Create your sample numbers:
var number1 = 30; var number2 = 75;
2. Check whether your numbers are within a range:
var constrained = number1.constrain(25, 50); // constrained is 30 because number1 is // within the specified range constrained = number2.constrain(25, 50); // constrained is 50 because number2 is // greater than the max. value in the range
Ext.Number is a one-function extension of the JavaScript Number object. The only function of Ext.Number is constrain(min, max), which simply uses methods of the Math JavaScript object to accomplish the range checks on the given number.
constrain: function(min, max) {
return Math.min(Math.max(this, min), max);
}