JavaScript compares two numeric size issues

Today encountered a problem, in the JS comparison two values of the size, according to the normal logic write dead and alive will not work.
The problematic code is as follows:

JS Code

2. function Chknum () {
4. var appcount = $ ("#appcount"). Val ();
6. var intencount = $ ("#intencount"). Val ();
8. var unemployment = $ ("#unemployment"). Val ();
10. if (appcount = = Null | | appcount = = "") {
12. Alert ("The number of candidates cannot be empty!")  ");
14. return false;
16. }
18. if (intencount = = Null | | intencount = = "") {
20. Alert ("The initial number of recruits cannot be empty!")  ");
22. return false;
24. }
26. if (Intencount < Appcount) {
28. Alert ("Initial employment should be less than the number of applicants!");
30. $ ("#intencount"). Val ("");
32. return false;
34. }
36. if (unemployment > Appcount) {
38. Alert ("The number of unemployed should be less than the number of applicants!");
40. $ ("#unemployment"). Val ("");
42. return false;
44. }
46. };

This problem tangled for a long time, the internet looked down JS incredibly have an eval function
eval function definition and usage
The eval () function computes a string and executes the JavaScript code in it.
The modified code

JS Code

2. function Chknum () {
4. var appcount = $ ("#appcount"). Val ();
6. var intencount = $ ("#intencount"). Val ();
8. var unemployment = $ ("#unemployment"). Val ();
10. if (appcount = = Null | | appcount = = "") {
12. Alert ("The number of candidates cannot be empty!")  ");
14. return false;
16. }
18. if (intencount = = Null | | intencount = = "") {
20. Alert ("The initial number of recruits cannot be empty!")  ");
22. return false;
24. }
26. if (eval (intencount) > eval (appcount)) {
28. Alert ("Initial employment should be less than the number of applicants!");
30. $ ("#intencount"). Val ("");
32. return false;
34. }
36. if (eval (unemployment) > eval (appcount)) {
38. Alert ("The number of unemployed should be less than the number of applicants!");
40. $ ("#unemployment"). Val ("");
42. return false;
44. }
46. };

JavaScript compares two numeric size issues