【Swift】配列の要素を置換する方法（ replaceSubrange ）

2021/8/23 2021/8/25 swift

Swiftで配列の要素を置換する方法について記載します。

配列の要素の置換方法

配列の置換には replaceSubrange メソッドを使用します。

replaceSubrange( 置換する範囲をインデックスで指定, 置換後の要素 )

1. 置換対象の要素数と置換後の要素数が同じ場合

次の例では、配列のインデックスが 1 〜 2 の範囲を置換しています。

// 文字列の配列を置換
var strs1 = ["a","b","c","d","e"]
var partStrs1 = ["B","C"]
strs1.replaceSubrange(1...2, with: partStrs1) // ["a", "B", "C", "d", "e"]

// 数値の配列を置換
var nums1 = [1,2,3,4,5]
var partNums1 = [20,30]
nums1.replaceSubrange(1...2, with: partNums1) // [1, 20, 30, 4, 5]

// 文字列の配列を置換

var strs1 = ["a","b","c","d","e"]

var partStrs1 = ["B","C"]

strs1.replaceSubrange(1...2, with: partStrs1) // ["a", "B", "C", "d", "e"]

// 数値の配列を置換

var nums1 = [1,2,3,4,5]

var partNums1 = [20,30]

nums1.replaceSubrange(1...2, with: partNums1) // [1, 20, 30, 4, 5]

2. 置換対象の要素数と置換後の要素数が異なる場合

要素数が異なる場合でも、先ほどと同様に置換できます。

// 文字列の配列を置換
var strs2 = ["a","b","c","d","e"]
var partStrs2 = ["B","C","●"]
strs2.replaceSubrange(1...2, with: partStrs2) // ["a", "B", "C", "●", "d", "e"]

// 数値の配列を置換
var nums2 = [1,2,3,4,5]
var partNums2 = [20,30,31,32,33]
nums2.replaceSubrange(1...2, with: partNums2) // [1, 20, 30, 31, 32, 33, 4, 5]

// 文字列の配列を置換

var strs2 = ["a","b","c","d","e"]

var partStrs2 = ["B","C","●"]

strs2.replaceSubrange(1...2, with: partStrs2) // ["a", "B", "C", "●", "d", "e"]

// 数値の配列を置換

var nums2 = [1,2,3,4,5]

var partNums2 = [20,30,31,32,33]

nums2.replaceSubrange(1...2, with: partNums2) // [1, 20, 30, 31, 32, 33, 4, 5]