如何在JavaScript中使用给定索引检索字符串中最接近的单词

【如何在JavaScript中使用给定索引检索字符串中最接近的单词】如果你想知道在具有指定索引号的字符串中哪个是最接近的单词, 请使用以下函数来解决问题：

/** * Find the word located in the string with a numeric index. * * @return {String} */function getClosestWord(str, pos) {// Perform type conversions.str = String(str); pos = Number(pos) > > > 0; // Search for the word's beginning and end.var left = str.slice(0, pos + 1).search(/\S+$/), right = str.slice(pos).search(/\s/); // The last word in the string is a special case.if (right < 0) {return str.slice(left); }// Return the word, using the located bounds to extract it from the string.return str.slice(left, right + pos); }

> > > 运算符将expression1的位右移expression2中指定的位数。零从左侧填充。右移的数字将被丢弃(左操作数的值将向右移动右操作数指定的位数, 并且移位后的值将填充为零)。
你甚至可以将此属性添加到String原型中：

String.prototype.closestWord = function (pos) {// Perform type conversions.str = String(this); pos = Number(pos) > > > 0; // Search for the word's beginning and end.var left = str.slice(0, pos + 1).search(/\S+$/), right = str.slice(pos).search(/\s/); // The last word in the string is a special case.if (right < 0) {return str.slice(left); }// Return the word, using the located bounds to extract it from the string.return str.slice(left, right + pos); }; "Hello, how are you".closestWord(5); // Outputs : Hello,

用法通常, 你可以使用诸如indexOf或string.search之类的函数来检索单词的索引：

var textA = "Hey, how are you today?"; var indexA = textA.indexOf("to"); var textB = "Sorry, i can't do this. Not today"; var indexB = textB.search("is"); var wordA = getClosestWord(textA, indexA); var wordB = getClosestWord(textB, indexB); console.log("Index A : " + indexA, wordA); console.log("Index B : " + indexB, wordB); // Output ://Index A : 17 today?//Index B : 20 this.

尽管这可能不是最常见的情况, 但是如果你在onboundary事件中使用API??(例如speechSynthesis), 该事件返回字符串中正在说出的单词的索引, 则它可能会变得有用。