在某些情況下用另一個字符串替換一個字符串

Question

如果y包括x的最后一個單詞，我想用y替換x的最后一個單詞。 我該如何處理？

let x ='jaguar lion tiger panda'
let y = 'pandas'

預期結果：

'jaguar lion tiger pandas'

如果

y = 'cat'

預期結果：

'jaguar lion tiger panda cat'

我嘗試過的代碼：

console.log(response)
let before = this.text.split(' ')
console.log(before)
console.log(before.length)
let a = before.slice(before.length-1)
console.log(a)
if (response.data.text[0].includes(a)) {
  let x = (before.slice(0, before.length-1))
  let y = x.replace(',', ' ')
  this.preResult = y.push(response.data.text[0])
} else {
  this.preResult.push(this.text + ' ' + response.data.text[0])

Answer 1

您可以使用正則表達式匹配最后一個單詞，然后通過檢查y是否includes單詞來進行測試。 如果是這樣，請用y替換單詞，否則請使用y串聯的原始單詞替換：

 const x ='jaguar lion tiger panda' const doReplace = y => x.replace( /\\S+$/, // match non-space characters, followed by the end of the string (word) => ( y.includes(word) ? y : word + ' ' + y ) ); console.log(doReplace('pandas')); console.log(doReplace('cat')); 

Answer 2

另一個解決方案：

  let x ='jaguar lion tiger panda' let y = 'pandas' let splited = x.split(' ') let lastWord = splited[splited.length - 1] if(y.indexOf(lastWord) >= 0){ splited[splited.length - 1] = y }else{ splited.push(y) } let result = splited.join(' ') console.log(result) 

Answer 3

function replaceLastWord(x, y) {
    let result = x.split(' '), lastIndex = (result.length || 1) - 1, lastWord = result[lastIndex]
    result[lastIndex] = y.indexOf(lastWord) !== -1 ?  y : `${lastWord} ${y}`
    return result.join(' ')
}

console.log(replaceLastWord('jaguar lion tiger panda', 'pandas'))
console.log(replaceLastWord('jaguar lion tiger panda', 'cat'))
console.log(replaceLastWord('', 'pandas'))