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Javascript 测试两个句子的起始字符_Javascript - Fatal编程技术网

Javascript 测试两个句子的起始字符

Javascript 测试两个句子的起始字符,javascript,Javascript,我正在努力学习有说服力的JavaScript,并进行了以下实践: 编写一个名为startsWith的函数,该函数接受两个参数,都是字符串。当第一个参数以第二个参数中的字符开头时,返回true,否则返回false 以下是他们给出的答案: function startsWith(string, pattern) { return string.slice(0, pattern.length) == pattern; } show(startsWith("rotation", "rot")); 但

我正在努力学习有说服力的JavaScript,并进行了以下实践:

编写一个名为startsWith的函数,该函数接受两个参数,都是字符串。当第一个参数以第二个参数中的字符开头时,返回true,否则返回false

以下是他们给出的答案:

function startsWith(string, pattern) {
return string.slice(0, pattern.length) == pattern;
}

show(startsWith("rotation", "rot"));
但我希望有一个更彻底的程序,可以把起始字符
chars
放到每个句子中进行测试,并说出每个句子中的起始字符是否相同。我是JavaScript和编程新手,因此任何帮助都将不胜感激!以下是我认为有效的方法:

var sentenceOne = "Pretty kitty doesn't like you!";
var sentenceTwo = "Preachy cat loves you.";
function startsWith(chars) {
  return (sentenceOne.slice(0, chars.length) == chars) == (sentenceTwo.slice(0, chars.length) == chars);
}
show(startsWith("pre"));

给出的答案相当详尽。给出两句话,你可以简单地做:

var sentenceOne = "Pretty kitty doesn't like you!";
var sentenceTwo = "Preachy cat loves you.";

show(startsWith(sentenceOne, "Pre") === startsWith(sentenceTwo, "Pre"));
show(startWith(sentenceOne, sentenceTwo, "Pre"));
您不需要一个全新的函数来检查两个字符串是否以相同的模式开头。请参见演示:


另一种方法是,给定两个句子和一个模式,您可以测试起始字符是否相同:

function startWith(sentenceOne, sentenceTwo, pattern) {
    return !(sentenceOne.indexOf(pattern) || sentenceTwo.indexOf(pattern));
}
现在您只需执行以下操作:

var sentenceOne = "Pretty kitty doesn't like you!";
var sentenceTwo = "Preachy cat loves you.";

show(startsWith(sentenceOne, "Pre") === startsWith(sentenceTwo, "Pre"));
show(startWith(sentenceOne, sentenceTwo, "Pre"));

请参阅演示:

您几乎已经拥有了它,但是您还必须通过参数(让我们调用它们
第一句
第二句
)将
第一句
第二句
传递给您的函数,以便它可以使用它们。否则,该信息不在功能范围内

var sentenceOne = "Pretty kitty doesn't like you!";
var sentenceTwo = "Preachy cat loves you.";
function startsWith(chars, firstSentence, sencondSentence) {
  return (sentenceOne.slice(0, chars.length) == chars) == (sentenceTwo.slice(0, chars.length) == chars);
}
show(startsWith("pre"), sentenceOne, sentenceTwo);

(句子1.slice(0,字符长度)=字符)和&(句子2.slice(0,字符长度)=字符);它可能会工作,但更明确的方法是:
返回sentenceOne.slice(0,chars.length)==chars&&sentenceTwo.slice(0,chars.length)==chars