问题描述:
In this kata, you will make a function that converts between camelCase
, snake_case
, and kebab-case
.
You must write a function that changes to a given case. It must be able to handle all three case types:
js> changeCase("snakeCase", "snake")"snake_case"js> changeCase("some-lisp-name", "camel") "someLispName" js> changeCase("map_to_all", "kebab") "map-to-all" js> changeCase("doHTMLRequest", "kebab") "do-h-t-m-l-request" js> changeCase("invalid-inPut_bad", "kebab") undefined js> changeCase("valid-input", "huh???") undefined js> changeCase("", "camel") ""
我的思路:
先将不符合要求的筛选出来,return undefined;
然后通过swich(targetCase),分别转换。
我的答案:
通过为171 / 174。问题出现在部分不符合要求的不能识别。
function changeCase(identifier, targetCase){ // Your code here! var a=["snake","camel","kebab"]; var id=identifier.split(""); if(identifier==""){ return "";} if(a.indexOf(targetCase)=="-1"|| (identifier.indexOf("-")!=-1 &&identifier.indexOf("_")!=-1 || (identifier.indexOf("-")!=-1 && identifier.indexOf(/A-Z/)!=-1) ||(identifier.indexOf(/A-Z/)!=-1 && identifier.indexOf("_")!=-1))){ return undefined;} switch(targetCase) { case "snake": for(var i=0;i
优秀答案:
(1)
function changeCase(identifier, targetCase){ if(!/^$|^[a-z]+(([A-Z][a-z]*)+|(-[a-z]+)*|(_[a-z]+)*)$/.test(identifier)) return undefined; switch(targetCase){ case 'snake': return identifier.replace(/-([a-z])|([A-Z])/g, (_,x,y) => '_'+(x||y.toLowerCase())); case 'camel': return identifier.replace(/[-_]([a-z])/g, (_,x) => x.toUpperCase()); case 'kebab': return identifier.replace(/_([a-z])|([A-Z])/g, (_,x,y) => '-'+(x||y.toLowerCase())); default: return undefined; }}
(2)
function changeCase(i, t){ if ( ( /[A-Z]/.test(i) + /[_]/.test(i) + /[-]/.test(i)) > 1 ) //这个好理解,当[A-Z],-,_,三者任意两个出现的时候,返回undefined return undefined; else if (t == "snake" ) return i.replace(/[A-Z]/g,a=>'_'+a.toLowerCase()).replace(/-([a-z])/g,(_,a)=> '_'+a);//先大写转“_”+小写,然后将所有-x转成_+小写 else if ( t== 'camel') return i.replace(/_/g,'-').replace(/-([a-z])/g,(_,a)=> a.toUpperCase()); //先_转-,然后将-后面的第一个字母大写 else if (t== 'kebab' ) return i.replace(/_/g,'-').replace(/[A-Z]/g,a=>'-'+a.toLowerCase());//先_转-,然后将大写字母小写}
(3)建议这个,方便好懂,前面两个正则略复杂,不易懂
将所有单词分开,放入到数组中。
当需要用的时候,按照snake/kebab/camel的格式连接。
function changeCase(identifier, targetCase){ if (identifier === '') { return ''; } if (/^[a-z-]+$/.test(identifier)) { identifier = identifier.split('-'); } else if (/^[a-z_]+$/.test(identifier)) { identifier = identifier.split('_'); } else if (/^[a-z][A-Za-z]+$/.test(identifier)) { identifier = identifier.replace(/([A-Z])/g, ' $1').toLowerCase().split(' '); //在大写字母前加空格,然后全部转小写,然后按空格分割 } else { return undefined; } switch (targetCase) { case 'snake' : identifier = identifier.join('_'); break; case 'kebab' : identifier = identifier.join('-'); break; case 'camel' : identifier = identifier.map( (x,i) => i === 0 ? x : x[0].toUpperCase() + x.slice(1)).join(''); break; default : return undefined } return identifier; }
哈哈哈!