iOS stringByEvaluatingJavaScriptFromString is not working in a simple code

Question

I wrote a piece of code about JS:

NSString *function1 = @"function getString(){return \"123\";}";
NSString *str = [theWebView stringByEvaluatingJavaScriptFromString:function1];
NSLog(@"str: %@", str);

but the "str" is not equal to "123", the result was

str:

Any help is appreciated。

There is a typo in your JS : "fuction". And even if that is fixed, the JS only defines the function, but never calls it. — Martin R
– Martin R, Commented Dec 24, 2013 at 7:52
you can understand it this way..a function cannot be called automatically. It has to be called. Suppose a script consists of several functions. You will need to explicitly call the function you need. This code doesn't automatically call the function. — mak
– mak, Commented Dec 24, 2013 at 8:44

Martin R · Accepted Answer · 2013-12-24 08:14:38Z

4

Your JavaScript code only defines the function getString, but never calls the function. Therefore the result of evaluating the script is empty.

If you actually call the function in the JavaScript

NSString *function1 = @"function getString() {return \"123\";} getString()";

you will get the expected result.

answered Dec 24, 2013 at 8:14

Martin R

541k98 gold badges1.3k silver badges1.4k bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Junfeng Li Over a year ago

OK! I did it. Thank you again.

Community · Accepted Answer · 2017-05-23 12:12:52Z

-1

This method mosf often usage for running java scripts based on current page contents. You can see similar question Here

But I've found example with definition of java script here

edited May 23, 2017 at 12:12

CommunityBot

11 silver badge

answered Dec 24, 2013 at 7:50

Ievgenii

1897 bronze badges

Collectives™ on Stack Overflow

iOS stringByEvaluatingJavaScriptFromString is not working in a simple code

2 Answers 2

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related