<script> var num = 1024; var mystr = num.toString(); console.log(mystr); // --------------------------- var mystr = String(num); console.log(mystr); // --------------------------- var mystr = "" + num; console.log(mystr); </script>
<script> // split()将字符串进行拆分返回一个新的数组 // split()的第二个参数,表示返回的字符串数组的最大长度 var mystr = "lbq,my,la,jjh"; var str = mystr.split(","); console.log(str); var str1 = mystr.split(",", 2); console.log(str1); </script>
<script> var mystr = "wozaijinxingzifuchuantihuancaozuo,zifuchuantihuano"; var str = mystr.replace("zifuchuan", ""); console.log(str); var str1 = mystr.replace(/zifuchuan/g, ""); console.log(str1); </script>
<script> var str = "itcast"; var mystr = str.length; console.log(mystr); </script>
<script> // indexOf() 返回字符串中一个子串第一处出现的索引(从左到右搜索) var str = "itcast"; var index = str.indexOf("t"); console.log(index); // lastIndexOf() 返回字符串中一个子串最后一处出现的索引(从右到左搜索) var index = str.lastIndexOf("t"); console.log(index); </script>
<script> // charAt()查找给定位置的字符 var mystr = "Hello World!"; var index = mystr.charAt(7); console.log(index); // charCodeAt()查找对应位置的字符编码值 var charCode = mystr.charCodeAt(7); console.log(charCode); </script>
<script> // match() var mystr = "hi,mynameisguoxiansheng6,33iswho?"; var matchStr = mystr.match("guo"); console.log(matchStr); // 正则匹配 var regexp2 = /guo/g; var matchStr = mystr.match(regexp2); console.log(matchStr); // search()若是查找成功,返回字符串中匹配的索引值。 var regexp1 = /guo/; var matchStr = mystr.search(regexp1); console.log(matchStr); </script>
<script> // 加法操做进行字符串链接 var mystr1 = "Hello"; var mystr2 = "world!"; var mystr3 = "li"; var newStr = mystr1 + " " + mystr2; console.log(newStr); // concat()传递多个字符串,拼接多个字符串 var newStr = mystr1.concat(mystr3 + mystr2); console.log(newStr); </script>
<script> // slice()函数: var mystr = "hello world!"; var mystr1 = mystr.slice(-3); console.log(mystr1); var mystr2 = mystr.slice(-3, -1); console.log(mystr2); var mystr3 = mystr.slice(3); console.log(mystr3); var mystr4 = mystr.slice(3, 7); console.log(mystr4); // substring()函数: var mystr = "hello world!"; var sliceStr1 = mystr.substring(3); console.log(sliceStr1); var sliceStr2 = mystr.substring(3, 7); console.log(sliceStr2); // substr()函数: var mystr = "hello world!"; var sliceStr1 = mystr.substr(3); console.log(sliceStr1); var sliceStr2 = mystr.substr(3, 7); console.log(sliceStr2); </script> 注: 1.slice() 能够为负数,若是起始位置为负数,则从字符串最后一位向前找对应位数而且向后取结束位置, 若是为正整数则从前日后取起始位置到结束位置。 2.substring()只能非负整数,截取起始结束位置同slice()函数一致。 3.substr()与第1、第二种函数不一样,从起始位置开始截取,结束位置为第二个参数截取的字符串最大长度。 以上三种函数未填第二参数时,自动截取起始位置到字符串末尾。
<script> var mystr = "Hello World!"; // toLowerCase() var lowCaseStr = mystr.toLowerCase(); console.log(lowCaseStr); // toUpperCase() var upCaseStr = mystr.toUpperCase(); console.log(upCaseStr); </script>
<script> // trim方法用来删除字符串先后的空格 var mystr = " hello world "; var trimStr = mystr.trim(); console.log(trimStr); </script>
<script> var str = "aahhgggsssjjj"; function removeRepeat(msg) { var res = []; var arr = msg.split(""); for (var i = 0; i < arr.length; i++) { if (res.indexOf(arr[i]) == -1) { res.push(arr[i]); } } return res.join(""); } var str1 = removeRepeat(str); //ahgsj console.log(str1);
1.先实现字符串去重javascript
2.而后对去重后的数组用for循环操做,分别与原始数组中各个值进行比较,若是相等则count++,
循环结束将count保存在sum数组中,而后将count重置为0java
3.这样一来去重后的数组中的元素在原数组中出现的次数与sum数组中的元素是一一对应的数组
var str = "aacccbbeeeddd"; var sum = []; var res = []; var count = 0; var arr = str.split(""); for (var i = 0; i < arr.length; i++) { if (res.indexOf(arr[i]) == -1) { res.push(arr[i]); } } for (var i = 0; i < res.length; i++) { for (var j = 0; j < arr.length; j++) { if (arr[j] == res[i]) { count++; } } sum.push(count); count = 0; } console.log(res); //["a", "c", "b", "e", "d"] for (var i = 0; i < res.length; i++) { var str = sum[i] % 2 == 0 ? "偶数" : "奇数"; console.log(res[i] + "出现了" + sum[i] + "次"); console.log(res[i] + "出现了" + str + "次"); } </script>