jquery - Validating javascript decimal numbers

Question

I'm using the following regexp to validate numbers in my javascript file:

var valid = (val.match(/^d+$/));

It works fine for whole numbers like 100, 200, etc, however for things like 1.44, 4.11, etc, it returns false. How can I change it so numbers with a decimal are also accepted?

Answer 1

var valid = (val.match(/^d+(?:.d+)?$/));

Matches:

 1  : yes
 1.2: yes
-1.2: no
+1.2: no
  .2: no
 1. : no

---

var valid = (val.match(/^-?d+(?:.d+)?$/));

Matches:

 1  : yes
 1.2: yes
-1.2: yes
+1.2: no
  .2: no
 1. : no

---

 var valid = (val.match(/^[-+]?d+(?:.d+)?$/));

Matches:

 1  : yes
 1.2: yes
-1.2: yes
+1.2: yes
  .2: no
 1. : no

---

var valid = (val.match(/^[-+]?(?:d*.?d+$/));

Matches:

 1  : yes
 1.2: yes
-1.2: yes
+1.2: yes
  .2: yes
 1. : no

---

var valid = (val.match(/^[-+]?(?:d+.?d*|.d+)$/));

Matches:

 1  : yes
 1.2: yes
-1.2: yes
+1.2: yes
  .2: yes
 1. : yes