# How to compare string in expression language

**URL:** <https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390>\
**Category:** Ignition\
**Tags:** vision, scripting, ignition80\
**Created:** [March 12, 2021, 5:28am UTC](https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390 "2021-03-12T05:28:33Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Premnath.K](https://avatars.discourse-cdn.com/v4/letter/p/b487fb/32.png) [@Premnath.K](https://forum.inductiveautomation.com/u/Premnath.K)\
**Post date:** [March 12, 2021, 5:28am UTC](https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390/1 "2021-03-12T05:28:33Z")

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Is there a way to compare to strings in an expression language?  
I just want to compare my local ip in the system network tag to specific ip in string format and enable/disable a button in vision based on the result.

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<div class="post-metadata">

**Author:** ![cmallonee](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/cmallonee/32/6416_2.png) [@cmallonee](https://forum.inductiveautomation.com/u/cmallonee)\
**Post date:** [March 12, 2021, 6:37am UTC](https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390/2 "2021-03-12T06:37:30Z")

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The [docs](https://docs.inductiveautomation.com/display/DOC81/Expression+Language+and+Syntax) should be pretty clear that it’s a simple comparison using `=`.

```auto
<your_ip> = "10.10.10.10"

```

No special function is needed.

In Perspective, the comparison would be done like this (although keep in mind that you might get a machine name instead of the IP):  
 ![Screen Shot 2021-03-11 at 10.41.00PM](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/8/d86c64156a0fb994e30b3a519fbe09612de72330.png)

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<div class="post-metadata">

**Author:** ![Premnath.K](https://avatars.discourse-cdn.com/v4/letter/p/b487fb/32.png) [@Premnath.K](https://forum.inductiveautomation.com/u/Premnath.K)\
**Post date:** [March 12, 2021, 7:24am UTC](https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390/3 "2021-03-12T07:24:43Z")

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Thanks for your input But I am using vision 8.0.15  
I tried this with an expression tag like this  
if ( {[System]Client/Network/IPAddress.Value} = “10.156.54.238” ,1,0)  
seems like could not compare strings

 ![expression binding2](https://us1.discourse-cdn.com/inductiveautomation/original/3X/7/3/73ac275a608147262e770363efacac5366317011.jpeg) ![expression binding1](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/3/6303ed360924339b1415b92a751a89c18fe2cc9f.jpeg)

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<div class="post-metadata">

**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [March 12, 2021, 10:11am UTC](https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390/4 "2021-03-12T10:11:51Z")

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You can just use `{[System]Client/Network/IPAddress} = "10.156.54.238"` or `! =`

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<div class="post-metadata">

**Author:** ![Premnath.K](https://avatars.discourse-cdn.com/v4/letter/p/b487fb/32.png) [@Premnath.K](https://forum.inductiveautomation.com/u/Premnath.K)\
**Post date:** [March 12, 2021, 11:36am UTC](https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390/5 "2021-03-12T11:36:30Z")

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Yeah, I tried this too without the if condition but the error is the same as the second attachment above.  
with an error message as below  
[false, Bad\_NotFound, Fri Mar 12 17:04:54 IST 2021 (1615548894049)]

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<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [March 12, 2021, 11:38am UTC](https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390/6 "2021-03-12T11:38:09Z")

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The problem isn’t string comparison. You are trying to use a tag that doesn’t exist in gateway context in an expression tag.

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**Author:** ![JordanCClark](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jordancclark/32/83362_2.png) [@JordanCClark](https://forum.inductiveautomation.com/u/JordanCClark)\
**Post date:** [March 12, 2021, 11:44am UTC](https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390/7 "2021-03-12T11:44:48Z")

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Adding to Phil’s comment, you need to make your expression tag in ‘Vision Client Tags’  
 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/b/9b025eac9092f226cea406cf99dd4daccf3cbc3f.png)

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<div class="post-metadata">

**Author:** ![Premnath.K](https://avatars.discourse-cdn.com/v4/letter/p/b487fb/32.png) [@Premnath.K](https://forum.inductiveautomation.com/u/Premnath.K)\
**Post date:** [March 12, 2021, 11:48am UTC](https://forum.inductiveautomation.com/t/how-to-compare-string-in-expression-language/44390/8 "2021-03-12T11:48:40Z")

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Thanks, pturmel and Jordan !  
Now able to compare after creating this expression in the client tag.