1. Find the string.
indexOf(Find from front to back.)lastindexOf(Look from back to front.)
indexOf('Need to find the character', start looking for from this index)
Returns the index position found, or -1 if not found.
var str = " abc defa";
console.log(str.indexOf('c',2));//1
searchmethod.
console.log(str.search("f"));//7
2. Element replacement.
replacemethod.
console.log(str.replace("a", 's'));//sbc defa
When replacing all identical characters in a string, regular expressions are required.
console.log(str.replace(/a/ig, 's'));//sbc defs
Has no effect on the original string.
3. The string is empty.
trimmethod.
console.log(str.trim());//abc defa
If you want to remove all the spaces in the middle, you need to use regularization.
console.log(str.replace(/\s/g, ''));//abcdefa
4. String splicing.
concatwith +.
var s1 = 'hdbhjbj';
var s2 = 'fdsadsadsa';
console.log(str.concat(s1, s2));//hdbhjbjfdsadsadsa
5. Get the character according to the character index.
charAtmethod.
console.log(str.charAt(1));//a
6. Return the ASCII value of the character according to the index.
charCodeAtmethod.
console.log(str.charCodeAt(1));//97
7. String interception.
substr(start position, length)substring(Start position, end position) take the smaller and not the larger.
console.log(str.substr(0,3));
console.log(str.substring(0, 6))
Has no effect on the original string.
8. Return the array after splitting by symbol.
splitmethod.
var s3 = "abcdefg";
console.log(s3.split(''));//['a','b','c','d']
9. Use the b tag to make it bold.
bold.big.blink.
10. Convert case.
Capitalize: toUpperCase, toLacalUpperCase.
Lower case: toLowerCase, toLocalLowerCase.
console.log(str.toLowerCase()); //abc defa
console.log(str.toUpperCase());//ABC DEFA
console.log(str.toLocaleLowerCase());// abc defa
console.log(str.toLocaleUpperCase());//ABC DEFA
11. Numbers are accurate to the decimal point.
toFixedmethod.
var num = 99;
console.log(num.toFixed(2));//99.00
12. Compare character ASCII values.
localeComparemethod.
var f1 = 'a';
var f2 = 'c';
console.log(f2.localeCompare(f1));//1
The big one is 1, and the small one is -1.