[igeek manual] daily algorithm 1 - string flip

Title : Flip a String

Target:

'hello' ——> 'olleh'

Ideas:

Convert the string into an array, and then use the reverse method of the array to reverse the order of the array, and then convert the array into a string.

Code:

function reverseString(str) {
    str = str.split('').reverse().join('')
    return str;
}

reverseString("hello");     // olleh

expand:

Common string methods
 charAt (num)          // Get the single character at the specified index position 
charCodeAt (num)      // Get the Unicode value of the character at the specified index position (ascii is a subset) 
concat (str01,str02)  // Concatenate two characters ~ 
indexOf ( "str" ​​)       // take the index of the first occurrence of str 
lastIndexOf ( "str" ​​)   // take the index of the last occurrence of str 
replace ( "oldStr" , "newStr" )  // find oldStr and replace it with newStr 
slice ( start , end )  // The object can be a string or an array, remember that the range does not include end 
substr (start, length) // length characters are taken from the index start, length cannot be less than 0, otherwise an empty string is returned


Common array methods
pop ()          // delete last item 
shift ()        // delete first item 
push ()         // add to last 
unshift ()      // add to first 
indexOf ()      // array element index 
slice ()        // intercept (slice ) array to get the intercepted array 
concat ()       // array merge 
reverse ()      // array flip

 

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Write it after:

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