如何关闭最后一个单词的空格，以便在它旁边插入一个句点？

Question

It has to do with the iteration length right? How do I iterate it all but the last index?

 function createSentence(words) { var sentence = ""; for (var i = 0; i < words.length; i++) { sentence += words[i] + ' '; if (i === words.length - 1) return sentence += '.'; } } var result1 = createSentence(['I', 'am', 'worth', 'it']); console.log('should log "I am worth it.":', result1); var result2 = createSentence(['My', 'problems', 'matter']); console.log('should log "My problems matter.":', result2);

Answer 1

Better idea: join by a space, then concatenate a single . onto the end afterwards:

 const createSentence = arr => arr.join(' ') + '.'; var result1 = createSentence(['I', 'am', 'worth', 'it']); console.log('should log "I am worth it.":', result1); var result2 = createSentence(['My', 'problems', 'matter']); console.log('should log "My problems matter.":', result2);

Answer 2

No looping is necessary. Just join all the array elements with a space and add a . to the end.

 function createSentence(words) { return words.join(" ") + "."; } console.log('should log "I am worth it.":', createSentence(['I', 'am', 'worth', 'it'])); console.log('should log "My problems matter.":', createSentence(['My', 'problems', 'matter']));

Answer 3

@CertainPerformance's solution is ideal.

If you want to avoid using join for educational purposes you could only append a space when i is not at the last position:

 function createSentence(words) { var sentence = ""; for (var i = 0; i < words.length; i++) { sentence += words[i]; if (i === words.length - 1) { return sentence += '.'; } else { sentence += ' '; // <--- } } } var result1 = createSentence(['I', 'am', 'worth', 'it']); console.log('should log "I am worth it.":', result1); var result2 = createSentence(['My', 'problems', 'matter']); console.log('should log "My problems matter.":', result2);