Xcode Swift - Is there an opposite to .contains?

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Is there a way to determine if string does not contain something in an if statement? Basically the opposite of .contains .

Example of contains:

if someItem.contains(x) {
code
}

Example of what I am looking for:

if someItem.doesNotContain(x) {
code
}

Where a slolution for doesNotContain is what I am looking for.

Any help is greatly appreciated, thank you.

*FYI, I am new to Swift and to programming, thank you for your comments.

No Apple doesn't provide any function like doesNotContain or something similar.

But if you don't want to add else part then you can simply use:

if !someItem.contains("hello") {
    //This means your someItem doesn't contain "hello" string.
}

contains(where:), contains(_:). Returns a Boolean value indicating whether the sequence contains the given element. Availability. Xcode 9.0+. Framework. Swift Standard Library. Swift 4 also introduces Optionals type, which handles the absence of a value. Optionals say either "there is a value, and it equals x" or "there isn't a value at all". An Optional is a type on its own, actually one of Swift 4’s new super-powered enums.

try using this way

if !someItem.contains(x) {
code
}

contains(_:), Unlike the arithmetic operators in C and Objective-C, the Swift arithmetic operators The nil-coalescing operator ( a ?? b ) unwraps an optional a if it contains a� Basic Operators¶. An operator is a special symbol or phrase that you use to check, change, or combine values. For example, the addition operator (+) adds two numbers, as in let i = 1 + 2, and the logical AND operator (&&) combines two Boolean values, as in if enteredDoorCode && passedRetinaScan.

Here are the results: First off, I removed "without using a true/false Boolean" from my question in order to avoid confusion and to better suit the answer/solution. Is there a code that is opposite to .contains? Simple Answer: NO. It turns out that contains(_:) is a Boolean in of itself. This I did not know since I am new to coding. The solution is actually quite simple as we can state this Boolean to be true or false, as suggested by @The Tiger.

if someItem.contains(x) == false

or

if someItem.contains(x)

Tested this, and works like a charm. Opens up a bunch of new oportunities for me, and I hope this helps out fellow coders in search of something like this.

Thank you all for your comments and helping me find the answer, Cheers.

Basic Operators — The Swift Programming Language (Swift 5.3), If it does contain the value, contains() returns true; if not, it returns false. return usedWords.contains(word) , then it would do the opposite: it would return true However, UIKit was written in Objective-C before Swift's strings came along, and it� Just like the Objective-C counterpart, we used if to see if the optional contains a value. Once we know the optional must contain a value, we unwrap it by placing an exclamation mark (!) to the end of the optional’s name. In Swift this is known as forced unwrapping. You use the ! operator to unwrap an optional and reveal the underlying value.

Checking for valid answers, Let's take a look at the Swift syntax for conditionals. course, and learn how to build great iOS 13 apps with Swift 5 and Xcode 11. An expression with the NOT operator returns the opposite of its value, so true when false� Swift program that splits with components, separatedBy import Foundation // An example string separated by commas. let line = "apple,peach,kiwi" // Use components() to split the string. Split on comma chars. let parts = line. components ( separatedBy: "," ) // Result has 3 strings.

Conditionals In Swift With If, Else If, Else – LearnAppMaking, In Swift you use conditionals to make decisions in your code, with if, else if and else. If this happens, then do that. This is called control flow, because you use it to control the way your code flows. In this article you’ll learn how to use the if-statement in your Swift code.

From: Matt Neuburg Book “iOS 13 Programming Fundamentals with Swift.” : To combine (concatenate) two strings, the simplest approach is to use the + operator:. let s = "hello" let s2 = " world" let greeting = s + s2

Comments
  • so you can use else part for that
  • Boolean negations can be done using NOT, the ! operator. There is also satisfyAll.
  • Its as simple as NO is the opposite of YES. if someItem.contains(x) == false OR if !someItem.contains(x).
  • @CrazyOne I'm still not getting why you need doesNotContain function. There are only two cases either it contains or not. So doesNotContain is same as contains == false. If you want to check if the string contains decimal or not then if !str.contains(".") will work. It depends on you that you want to write the code in if block or else block but this is correct.
  • @CrazyOne Feel free to ask any query if you have any confusion. I have No problem.