从 .txt 文件中抓取单词 - Java

Question

I have been tasked to grab 100 words, at random, from a dictionary.txt file. I have been able to read to the file using a scanner, populate an array based on each new line (which would separate the words + definitions to a single element each) and then formatted it to remove the brackets. However, now I need to figure out how to grab just the first word from each array element, possibly by using a regex or the fact that it is the first word in each element being ended by a space.

My question is how would one go about grabbing just the first word out of every array element, or, as mentioned below, grab the first word per line.

Answer 1

You probably just want to use yourString.split(" ")[0] .

However, I believe constructing an array of all the lines is wasteful. You could instead construct an array of the first words of the file using a Scanner, or you could even do a first parse to count the number of lines and then only construct the final desired result.

Oh and a last edit for your regex culture : the appropriate regex would have been ^\\S+ which grabs all non-space characters at the start of a string. It's most probably less efficient than using String.split() .

Answer 2

The easiest way to grab the first word from each line would be by using indexOf() and substring() :

String[] lines = new String[100];
String[] words = new String[100];
int x;

//your code for getting the lines of text from the file goes here

for (int i=0; i<lines.length; i++) {
    x = lines[i].indexOf(" ");
    words[i] = lines[i].substring(0, x);
}